4x6 Shipping Labels vs A6 vs 100x150: What’s the Difference?

Why these three label names confuse shoppers

The confusion around 4x6 shipping labels, A6 labels, and 100x150 labels usually starts with one simple problem: three different naming systems are describing sizes that look almost the same at a glance. One uses inches, one uses an ISO paper standard, and one uses millimetres. That is why shoppers end up staring at product pages, printer settings, or courier templates wondering whether they are comparing the same thing or three completely different products. It feels a bit like shopping for shoes when one store uses US sizes, another uses EU sizes, and a third just tells you the foot length in centimetres. The labels may seem interchangeable, but the details matter.

This naming mess gets worse in ecommerce because many sellers shorten, round, or simplify dimensions. A listing may say 4x6, another may say 100x150mm, and a third may throw in A6 because it sounds close enough to the eye. The problem is that “close enough” is not always good enough when you are printing barcodes, QR codes, addresses, or courier labels that must fit within a defined printable area. A few millimetres can mean the difference between a perfectly centered label and one that gets cropped, scaled, or leaves extra blank borders.

There is also a practical reason people mix these terms up: thermal printers often support more than one naming format in the software. A printer menu might show 4x6, a label supplier may list the roll as 100x150, and someone familiar with office paper sizes may assume A6 is the same thing. That chain reaction creates purchase mistakes, wasted label stock, and frustrating printer setup issues.

The good news is that this confusion is easy to untangle once you separate the naming systems. 4x6 and 100x150 are usually talking about nearly the same shipping label format in real-world ecommerce use. A6 is the one that sounds similar but is actually different. Once you know that, buying the right labels becomes much simpler.

The quick answer: which names match and which do not

Here is the clean, practical answer most buyers are looking for: 4x6 and 100x150 usually point to the same kind of shipping label in everyday ecommerce language, while A6 is a different size. That is the heart of the confusion. People often assume all three are interchangeable because they sit in roughly the same visual ballpark, but only two of them are close enough to be grouped together for most shipping-label shopping. A6 is not a true 4x6 equivalent.

A true 4x6 label measures 4 x 6 inches, which converts to 101.6 x 152.4 mm. A 100x150 label measures 100 x 150 mm, which is slightly smaller than true 4x6 by 1.6 mm in width and 2.4 mm in height. In practice, that tiny difference is often treated as nominal or rounded sizing on product pages, which is why many thermal label products, printer settings, and marketplaces use the terms almost interchangeably. By contrast, A6 measures 105 x 148 mm. That means it is wider but also shorter than 4x6, and the aspect ratio is different too. That shape difference matters more than many buyers expect.

So what should a shopper remember? Think of 4x6 and 100x150 like two road signs pointing to nearly the same destination. A6 is the road that looks close on the map but takes you somewhere slightly different. When you are buying labels for a thermal shipping workflow, that difference can affect printer setup, software templates, and how neatly your courier label fits the stock. That is why checking the exact dimensions is always smarter than trusting the label name alone.

What 4x6 shipping labels actually measure

When a product says 4x6 shipping labels, it is using imperial measurements. The label is meant to be 4 inches wide and 6 inches tall, which converts to 101.6 mm x 152.4 mm. That size has become one of the most common formats for thermal shipping labels because it gives enough room for sender and receiver details, tracking barcodes, routing information, and any extra courier markings without cramming everything into a tight space. It is big enough to be easy to scan, but still compact enough to fit cleanly on satchels, cartons, padded mailers, and small parcels.

A lot of sellers assume “4x6” is just casual shorthand, but it is actually a very useful reference point. When a printer says it supports 4x6 labels, it usually means the printer is designed for the shipping-label format most marketplaces, courier systems, and warehouse workflows expect. That makes life easier because many label templates are already designed around this approximate size. You are not constantly resizing PDFs or fiddling with margins like you would with office paper. The format is almost like the plain white T-shirt of shipping labels: basic, dependable, and compatible with almost everything.

What catches people out is that 4x6 is not the same thing as “any label that looks about that size.” A few millimetres can change how content sits on the stock. On a thermal printer, that may show up as clipped borders, tiny white gaps, or barcodes sitting too close to the edge. Even when the printer can physically handle the label, the wrong template setting can shrink or stretch the print job. That is why the term 4x6 shipping labels is best treated as a specific format, not just a rough category.

For online sellers, the term also acts like a search shortcut. When buyers search for 4x6 thermal shipping labels, they are usually looking for the standard thermal label format used in ecommerce dispatch. That is why the phrase keeps appearing across printer listings, label rolls, and shipping-supply pages. It is the language most sellers recognize right away.

Why 4x6 became the default shipping format

The reason 4x6 became so common is simple: it hits a sweet spot between visibility, scannability, and printing efficiency. Shipping labels need room for addresses, service information, tracking numbers, and barcodes that scanners can read quickly. If a label is too small, the barcode gets compressed and text becomes hard to scan or hard to read. If it is too large, it wastes stock and takes up more parcel space than necessary. 4x6 settled into that practical middle ground, which is why it became the go-to format for so many shipping workflows.

There is also a workflow reason behind its popularity. Thermal printers are built to handle labels quickly, one after another, with minimal setup. A 4x6 shipping label works beautifully in that environment because the size is large enough for clear courier formatting but still standardized enough to work across many systems. It is the warehouse equivalent of using a universal charging cable. When one format becomes familiar and dependable, businesses build around it. Label software, printer drivers, packing stations, and order-management tools start treating it like the default.

Another reason the format stuck is that it works across a wide mix of packaging types. A small box, a poly mailer, and a padded satchel can all take a 4x6 label without much drama. That means sellers do not have to rethink their label size every time they change packaging. For growing stores, that consistency matters. It reduces training time for staff, lowers the risk of print errors, and keeps dispatch speed smooth during busy periods.

That is why people searching for shipping labels often begin with 4x6, even if the product they eventually buy is listed as 100x150 mm. The name 4x6 has become the everyday language of thermal shipping labels. It is less about strict geography and more about habit. Sellers, couriers, and label suppliers understand it, so it continues to dominate the conversation around thermal shipping supplies.

What A6 actually means

A6 is not a shipping-label measurement system. It is part of the ISO 216 A-series paper standard, the same family that includes A4, A5, and A3. In that system, A6 measures 105 x 148 mm. That makes it a standardized paper size, not a label size invented specifically for courier workflows. This is where a lot of confusion begins. Because A6 sits visually close to the footprint of a 4x6-style label, people assume they are describing the same thing. They are not.

The biggest clue is the shape. A6 has a different aspect ratio from 4x6. A true 4x6 label follows a 2:3 ratio, while A6 follows the paper ratio used throughout the A-series. That means even when the width and height seem broadly similar, the content does not land on the page the same way. A template designed for a 4x6 shipping label can look slightly squeezed, cropped, or padded when printed on A6 stock. That shape mismatch is the part many buyers miss because the difference sounds small on paper but becomes obvious once a barcode or address block is involved.

Another key point is purpose. A6 is commonly associated with office, stationery, postcard, flyer, and document-style uses. It can absolutely be used for printed content, notes, inserts, and small informational cards. But when someone is specifically buying thermal shipping labels, A6 is not the default language used in that category. So when a listing uses A6 in a shipping context, it is worth slowing down and checking the exact dimensions rather than assuming compatibility.

That does not mean A6 is wrong or useless. It simply belongs to a different sizing ecosystem. The trouble comes when buyers mix an office-paper standard with a courier-label standard and expect the printer or template to magically smooth over the difference. Thermal printers are practical machines, not mind readers. They will print what the settings tell them to print, which is why choosing the right size name matters more than people think.

Why A6 is often mistaken for shipping-label size

A6 gets mistaken for a shipping-label size because the numbers look comfortingly close to 4x6. On a product page, 105 x 148 mm does not feel wildly different from 100 x 150 mm or 101.6 x 152.4 mm. To the eye, it can seem like one of those harmless rounding situations where a brand simply chose a different naming style. That is why buyers often toss A6 into the same mental basket as 4x6 and 100x150. The resemblance is real enough to create confidence, but not accurate enough to guarantee a clean print result.

There is also a language shortcut at play. Many shoppers are already familiar with A4 paper, so when they see A6, it feels official and standardized. That familiarity can make it seem safer than a label described in inches. In reality, though, the fact that A6 is standardized is exactly why it differs from 4x6. It is standardized to the A-series paper ratio, not to the shipping-label format most thermal systems are built around.

Some marketplaces and sellers add to the confusion by using broad product titles or mixed keywords to catch search traffic. A listing might mention A6, 4x6, and 100x150 in the same title because shoppers search all three. That helps visibility, but it can blur the real distinction between paper size and label size. The buyer sees all three terms together and assumes they are interchangeable. Later, the printer setup proves otherwise.

The practical danger is not that A6 is unusable. The danger is assuming it is a drop-in replacement for 4x6 thermal shipping labels. That assumption can lead to wasted stock, off-center prints, or labels that need scaling before they fit properly. For cards, inserts, or general print jobs, A6 may be perfect. For shipping labels, the safer mindset is this: A6 is adjacent, not identical. Once you understand that, the whole naming puzzle becomes much easier to solve.

What 100x150 actually means

When a label is described as 100x150, the measurement is being given in millimetres. That means the label is 100 mm wide and 150 mm tall. In ecommerce and thermal-label shopping, this size is commonly treated as the metric version of the familiar 4x6 shipping label. Strictly speaking, it is not an exact conversion, because a true 4x6 label is 101.6 x 152.4 mm. Still, the difference is small enough that many suppliers, marketplaces, and printer brands use 100x150 as the practical naming format for the same style of shipping label.

This is why so many product pages make shoppers pause. A person searching for 4x6 shipping labels may land on a page full of 100x150 mm stock and wonder whether they are looking at the wrong thing. In many cases, they are not. The seller is simply using metric naming because that is the convention in their catalogue, region, or manufacturing specification. The important thing is understanding that 100x150 usually belongs to the same family of thermal shipping labels as 4x6, not to the A-series paper family.

There is also a manufacturing and retail reality behind this. Product descriptions often use nominal size, not ultra-precise conversion language. A supplier might round dimensions to the nearest clean metric number because it makes the listing easier to read and easier to search. Buyers then see 100x150 and assume it must be distinctly different from 4x6, when the product was actually designed to serve the same shipping purpose all along. That naming shortcut is practical, but it does create hesitation for first-time buyers.

The safest way to read 100x150 is this: it is usually the metric label name you will encounter when shopping outside inch-based catalogues. In daily ecommerce use, it is often the direct alternative naming convention for 4x6-style shipping labels. That is why printer support pages, label rolls, and warehouse teams often use the two terms almost side by side. The language changes, but the job the label is meant to do stays largely the same.

Why online stores and printer brands use metric naming

Online stores and printer brands use metric naming because millimetres are often easier to standardize across international catalogues, packaging specs, and manufacturing workflows. Inches dominate some markets, but metric dimensions make product databases cleaner when a business sells across different regions. A printer brand may list support for 100x150 mm because that format speaks to a global audience, while sellers and warehouse operators still casually refer to the same label as 4x6. Both are trying to describe the same shipping-label use case, just through different measurement languages.

There is also a practical search-engine reason. Buyers do not all search the same way. Some type 4x6 thermal labels, others search 100x150 shipping labels, and some look for shipping label printer 100x150 because that is how the printer settings appear on their device. Stores that understand this naming split often include both versions in product titles and descriptions. That is smart merchandising, but it can make shoppers feel like they are choosing between two products when they are actually looking at one familiar format.

Printer interfaces add another layer. Depending on the brand, you may see media presets written as 4x6, 100 x 150 mm, or a custom-size field where you enter the exact dimensions yourself. That means a buyer can see one name on the product page, another in the printer driver, and a third in the shipping platform. Without context, it feels messy. With context, it makes perfect sense: the printer is not disagreeing with the product page; it is just speaking a different measurement dialect.

That is why the smartest way to shop is to focus less on the headline label name and more on the actual dimensions plus intended use. If the product is meant for thermal shipping workflows and the sizing sits in the 4x6 / 100x150 range, you are usually on the right track. Metric naming is not a warning sign. It is simply the language many suppliers use to describe a globally familiar shipping-label format.

4x6 shipping labels vs A6: the practical difference

When buyers compare 4x6 shipping labels vs A6, the practical difference comes down to two things: dimensions and shape. A true 4x6 label measures 101.6 x 152.4 mm. A6 measures 105 x 148 mm. That means A6 is a little wider and a little shorter. On paper, those numbers do not look dramatic. In print, they can be surprisingly important. A courier label template designed for 4x6 expects a certain balance of width and height. Change that balance, and the elements on the label may no longer sit where they should.

This matters most for barcodes and address blocks. Shipping labels are not like casual flyers where a small size mismatch usually goes unnoticed. They are functional documents that need to print cleanly and scan reliably. A barcode pushed too close to an edge, an address block slightly reduced to fit, or a QR code scaled awkwardly can create problems at dispatch. Sometimes the label still works. Sometimes it scans after a second try. Sometimes it looks fine until a courier system rejects the layout or the label prints with clipped margins. That uncertainty is exactly what most sellers are trying to avoid.

Another difference is compatibility language. 4x6 is the phrase most closely tied to the thermal-shipping world. A6 belongs more naturally to paper products, office supplies, inserts, postcards, and general print formats. So when a seller is choosing between the two for shipping, 4x6 usually gives clearer compatibility with thermal printers, shipping templates, and courier-ready workflows. It is the more direct signal that the product was intended for parcel-label use.

Think of it like buying a phone case. Two phones may be nearly the same size, but “nearly” does not guarantee the buttons, camera cutout, and edges will line up perfectly. That is the difference between A6 and 4x6. They are neighbours, not twins. For general printing, that may be fine. For thermal shipping labels, that small mismatch can become an annoying daily problem. That is why buyers looking for reliable courier-label performance are usually better served by sticking with 4x6 or 100x150, not A6.

4x6 shipping labels vs 100x150: are they the same?

This is the comparison that trips people up the most, because the honest answer is slightly nuanced. 4x6 and 100x150 are not mathematically identical, but in ecommerce they are often treated as the same shipping-label format. A true 4x6 label converts to 101.6 x 152.4 mm. A 100x150 label is 100 x 150 mm. So yes, there is a measurable difference. But it is small enough that many suppliers, printers, and buyers use the two names almost interchangeably when talking about thermal shipping labels.

That tiny difference matters less than the intended workflow. If a label product is marketed for shipping, supports common thermal printers, and sits in the 4x6 / 100x150 category, it is generally being sold for the same job. In many real-world cases, the term 100x150 functions like a metric retail label for 4x6-style shipping stock. That is why shoppers so often see both terms attached to similar products. Sellers are not necessarily being sloppy; they are speaking to different search habits and regional naming preferences.

Still, precision lovers are right to ask the question. A few millimetres can matter when your printer settings are rigid or your label software scales content too aggressively. That is why it helps to separate shopping language from technical conversion language. From a shopping perspective, 4x6 and 100x150 usually live in the same bucket. From a strict measurement perspective, they are not exact twins. Both statements can be true at the same time.

The practical takeaway is straightforward. When you see 100x150, do not panic and assume it is unrelated to 4x6 shipping labels. Check the printer compatibility, confirm the intended use, and look at the actual dimensions. In most thermal shipping contexts, 100x150 is the metric shorthand buyers use when they mean the familiar 4x6-style label. It is much closer to 4x6 than A6 ever is. For everyday dispatch work, that is the comparison that matters most.

Which size should you buy for your store and printer?

For most ecommerce stores, the safest answer is this: buy 4x6-style thermal shipping labels, whether they are named 4x6 or 100x150. That is the size family most closely associated with shipping workflows, and it is the one buyers tend to mean when they search for courier-label stock. A6 is better treated as a separate option rather than a substitute. It may work in some custom setups, but it is not the default recommendation for a business that wants a smooth plug-and-play shipping process.

The right choice also depends on what your printer supports natively. Some printers advertise support in inches, some in millimetres, and some list a maximum width rather than a named label size. That is why the smartest buying habit is to compare three things together: printer specs, label dimensions, and template settings. If those three line up, printing becomes easy. If one of them speaks a different size language, confusion sneaks in quickly. A label roll is never just a roll; it is part of a system.

Here is a simple buying lens:

For stores shipping daily, consistency matters more than theoretical flexibility. You do not want your team asking whether today’s roll is “close enough.” You want a label that loads, calibrates, and prints without fuss. That is why the most practical move is to standardize your workflow around the shipping format your printer and software expect. In most cases, that means 4x6 or 100x150, not A6. One clean system will always beat three almost-compatible ones.

Choosing the right printer and label roll for daily shipping

Choosing the right setup is not only about the label size name. It is about how the printer, label stock, and shipping software behave together during daily use. That is where many buying mistakes happen. A seller focuses on the headline size, buys a roll that looks correct, and then discovers the printer driver is set to a different template, the sensor calibration is off, or the software scales the PDF unexpectedly. Suddenly the problem looks like “bad labels” when the real issue is system mismatch.

That is why it helps to think in layers. First, confirm the printer is built for thermal shipping labels rather than general office printing. Second, check whether it supports the 4x6 / 100x150 class of labels as a native or recommended format. Third, make sure the label stock itself is described for shipping use, not just for general-purpose tags or paper printing. That three-part check removes most of the confusion before you even place an order.

For businesses that want a cleaner buying path, it makes sense to shop a product range built around the standard shipping-label workflow rather than trying to reverse-engineer random size names from generic listings. A collection like 4x6 thermal shipping labels is useful precisely because it anchors the purchase around the format people actually use for ecommerce shipping. Instead of debating whether a listing means A6, metric, or imperial shorthand, you start with the workflow that matches parcel-label printing.

A good daily shipping setup should feel boring in the best possible way. Load the labels, print the order, stick it on the parcel, move on. That kind of reliability comes from choosing supplies that match the real shipping format your store uses. If a product page clearly connects the printer and stock to 4x6-style thermal shipping labels, you are usually standing on much firmer ground than when you buy based on broad size guesses alone. In shipping, boring is beautiful. Smooth repetition is what saves time, reduces waste, and keeps dispatch moving.

Conclusion

The whole 4x6 shipping labels vs A6 vs 100x150 debate becomes much less confusing once you stop treating the three names as equals. 4x6 is the familiar shipping-label format named in inches. 100x150 is the metric version commonly used to describe that same style of thermal shipping label in product catalogues and printer settings, even though it is not a mathematically perfect inch-to-millimetre conversion. A6, on the other hand, belongs to a different sizing system and has a different shape. It may look close, but it is not the same fit for standard shipping-label workflows.

That distinction matters because shipping labels are functional tools, not decorative prints. A few millimetres can affect scaling, margins, barcode placement, and how neatly the template sits on the stock. For general print jobs, near enough may feel acceptable. For ecommerce dispatch, the goal is repeatable accuracy. You want the label to print cleanly, scan fast, and fit the parcel without a second thought. That is why the most practical buying mindset is to treat 4x6 and 100x150 as the key shipping-label search terms, while treating A6 as a separate size altogether.

So which term should you trust when you shop? Trust the dimensions, the printer compatibility, and the intended use. If the product is built around thermal shipping workflows and is sold as 4x6 or 100x150, you are usually in the right place. If it is described as A6, slow down and check whether it is really meant for courier-label printing. That one habit can save a lot of wasted stock and unnecessary frustration.

For most online sellers, the simplest path is to standardize around 4x6-style thermal shipping labels and build the rest of the workflow around that. Once you do, the naming confusion stops feeling like a puzzle and starts feeling like background noise you already know how to ignore.

FAQs

Is 4x6 exactly the same as 100x150?

Not exactly. A true 4x6 label measures 101.6 x 152.4 mm, while 100x150 measures 100 x 150 mm. So if you are looking at the numbers with a ruler in hand, there is a difference. The metric version is slightly smaller. That said, the gap is tiny enough that in normal ecommerce shopping, suppliers and printer brands often use 100x150 to describe the same type of shipping-label format buyers commonly call 4x6. That is why the two names show up side by side so often.

The important part is not just the math; it is the intended use. When a product is marketed for thermal shipping and listed as 100x150, it is usually meant to sit in the same practical category as 4x6 shipping labels. In other words, the listing language may differ, but the workflow goal is the same. Sellers know buyers search using both terms, so both names become part of the conversation.

Where people get tripped up is assuming all “almost the same” sizes behave the same under every printing condition. They do not. Some printers and software templates are forgiving, and some are fussy. That is why checking the actual supported media size in your printer settings is still worth doing. Think of 100x150 as the metric cousin of 4x6: close enough to share the family table, but not a literal clone.

For buying decisions, the safest summary is this: 100x150 is usually the right place to look when you want 4x6-style shipping labels, especially in metric-based catalogues. Just do not confuse that practical equivalence with exact physical identity.

Why does A6 look close to 4x6 but print differently?

A6 looks close to 4x6 because the footprint seems similar at first glance. That visual similarity is what tricks so many buyers. But once you compare the actual measurements, the difference becomes clear. A6 is 105 x 148 mm, while 4x6 is 101.6 x 152.4 mm. So A6 is a bit wider and a bit shorter. More importantly, the proportions are different. A6 follows the A-series paper ratio, while 4x6 follows a 2:3 ratio. That difference in shape affects how a shipping template sits on the label.

In practical terms, a label design built for 4x6 expects a certain vertical balance. The barcode, address block, service icons, and margins are arranged with that rectangle in mind. Put the same layout onto A6, and something often has to give. The software may shrink the content, push it inward, clip the edges, or leave inconsistent white space. None of those outcomes is ideal when your label needs to look clean and scan reliably.

This is why A6 is such a sneaky source of confusion. It is not wildly wrong, so buyers assume it must be fine. But “not wildly wrong” is a poor standard for shipping operations. Thermal label printing works best when the media and template match closely. That is how you avoid surprises at the packing bench.

So yes, A6 can look like a close cousin to 4x6. But in printing terms, it behaves differently because the dimensions and aspect ratio are different, not just the name. That distinction is exactly why shoppers comparing 4x6 shipping labels vs A6 need to look beyond appearances and focus on exact sizing.

Can a thermal printer switch between A6 and 4x6 labels?

Many thermal printers can physically handle more than one label size, but that does not mean switching between A6 and 4x6 is always seamless. The printer’s hardware may accept both widths or lengths, yet the real challenge sits in the setup. You need the correct media size selected in the driver, the correct template in the shipping software, and sometimes a fresh calibration so the sensor reads the label gap properly. Without those adjustments, a printer that “supports” multiple sizes can still produce messy results.

This is why buyers should separate printer capability from workflow convenience. A printer may be technically flexible enough to print both sizes. But if your daily dispatch system is designed around 4x6 shipping labels, introducing A6 into the mix adds friction. Someone has to change the settings, verify the preview, and watch for scaling or cropping issues. That may be fine for occasional specialty jobs. It is much less appealing for repetitive shipping work where speed and consistency matter most.

There is also the issue of template origin. Many courier labels and shipping PDFs are generated with the 4x6-style format in mind. Even if the printer can output A6, the label file itself may not sit naturally on that stock. That is where users run into clipped edges or extra margins and start blaming the printer, even though the mismatch started with the media size.

So yes, a thermal printer can often switch sizes, but the better question is whether that switch makes sense for your dispatch process. For most stores, it is easier to choose one dependable shipping-label format and stick with it. In real-world ecommerce, that usually means standardizing on 4x6 or 100x150, then keeping the whole workflow aligned around that choice.

Will courier barcodes still scan if the label size is slightly off?

Sometimes they will, and sometimes that “slightly” creates more trouble than you expect. Barcode scanning depends on several factors working together: the print quality, the barcode size, the quiet zones around it, the contrast of the thermal print, and the overall placement on the label. A small size mismatch does not automatically ruin a label, but it can push the barcode closer to the edge, compress the image, or change the scaling in a way that reduces scan reliability. That is why a label can look acceptable to the human eye yet still be less than ideal for courier equipment.

Thermal printers are pretty unforgiving in this area because they are built for precision and repetition. If the software thinks it is printing on 4x6, but the stock is actually A6 or another near-match, the label may be resized to fit. That resize can shrink barcodes or alter spacing. The result may still scan on your phone camera or a basic handheld scanner, but a fast-moving warehouse or courier sorting system is less patient. Reliable shipping is not about “can it scan once?” It is about “will it scan quickly every time?”

That is why consistent sizing matters. A tiny difference between 4x6 and 100x150 is often manageable because those formats live in the same practical shipping world. A bigger mismatch in shape, like A6 vs 4x6, is more likely to produce layout shifts that affect barcode presentation. The risk is not always dramatic, but it is real enough to matter for businesses shipping at scale.

The safest habit is to match the template to the label size instead of hoping the scanner forgives the mismatch. That approach keeps barcodes crisp, margins predictable, and dispatch headaches to a minimum. Shipping labels are one of those areas where precision quietly pays for itself.

What should I search for when buying replacement labels online?

The best search terms depend on the workflow you want, not just the size name that first comes to mind. If you are buying for ecommerce dispatch, start with 4x6 thermal shipping labels. That phrase usually pulls up the most relevant results because it combines the common shipping format, the print technology, and the intended use. It is far more useful than searching something vague like “large labels” or “printer labels,” which can flood the results with office stickers, mailing labels, and unrelated stationery products.

It also helps to search with alternate naming built in. Good terms include 4x6 shipping labels, 100x150 thermal labels, 100x150 shipping labels, and thermal label printer 4x6. Those variations catch both imperial and metric listings. That matters because some stores catalogue the same type of label under 4x6, while others prefer 100x150 mm. Searching both helps you avoid the false impression that one site has the “right” product and another has a different one when both are actually describing the same shipping-label family.

What you should not do is rely on A6 as your main shipping-label search term unless you specifically want A6-sized stock for a separate purpose. A6 can surface products that are not aimed at standard courier-label workflows, which increases the chance of buying stock that looks close but behaves differently in print.