Barcode size requirements: EAN-13 printing guide

An EAN-13 barcode printed at its nominal (100%) size measures about 37.29 mm wide and 25.93 mm high, including the human-readable digits, and GS1 allows retail barcodes to be scaled between 80% and 200% of that size. To scan reliably it also needs black (or very dark) bars on a white or light background, its full bar height, a clear blank margin on both sides, and a flat spot on the pack away from edges, folds and seams.

Those are the barcode size requirements in two sentences. This guide explains each rule in practical terms: what the X-dimension is and why it matters more than "percent", how much white space a quiet zone needs, which colour combinations work and which fail, where to put the code on a box, bottle or bag, and how to print labels on a desktop or thermal printer without falling below the minimum size. It finishes with a test routine and a printable checklist.

The guide is written for small brands and online sellers who print their own labels or brief a packaging printer. It covers the classic one-dimensional EAN-13 and UPC-A barcodes you see on almost every consumer product, plus a short look at the 2D codes that are being added next to them. If you are still working out what the 13 digits mean, start with our complete guide to EAN codes and come back here when you are ready to print.

Before you print: is the number itself correct?

A perfectly printed barcode is worthless if it carries the wrong number. It helps to keep two things apart. The GTIN (Global Trade Item Number) is the number. The EAN-13 barcode is the symbol, the pattern of bars that carries that number to a scanner. You can generate the barcode image yourself for free from a number you own, but you cannot make up the number. As Shopify's German guide puts it, generating your own EANs is risky because of duplicates, while the barcode image itself "can be created without issue".

So before anything goes to the printer, run three quick checks:

1. Length and check digit. An EAN-13 has exactly 13 digits and the last one is a check digit calculated from the other twelve. One wrong digit and the barcode either will not scan or will scan as a different product. Use the calculator below, or read how the EAN check digit is calculated.
2. The right number for this exact item. Each size, colour, flavour and pack size needs its own number. A black sock in size 39–42 and the same sock in 43–46 are two products with two barcodes, and a 3-pack is a third. If you are unsure, our guide to EANs for variants, bundles and product changes walks through the rules.
3. The same number in your listings. Compare the digits in your webshop, marketplace listing and stock system with the number on the artwork, digit by digit. Copy-paste errors at this stage are common and expensive once 5,000 boxes have been printed.

The check digit only catches typing and scanning errors. It does not prove that a code is registered to you or anyone else. Google's Merchant Center help, for instance, tells sellers to verify the check digit with GS1's calculator, but that is purely a format check.

What size should an EAN-13 barcode be?

The starting point for every EAN-13 is its nominal size, also called 100% magnification. At 100% the full symbol, including the quiet zones and the digits printed under the bars, is about 37.29 mm wide and 25.93 mm high. A UPC-A, the 12-digit North American version, is almost identical at about 37.29 × 25.91 mm.

You do not have to print at exactly 100%. GS1 Netherlands states that "the specified magnification range for an EAN13 barcode symbol scanned at retail is between 80% … and 200%". In other words, the whole barcode can shrink to 80% of nominal for small packs or grow to 200% for large ones, as long as it is scaled in proportion.

EAN-13 sizes at common magnifications

The table below scales the nominal dimensions. Because the width includes the quiet zones, it is the total space you need to reserve on the artwork, not just the width of the bars.

Magnification	X-dimension (narrowest bar)	Approx. width incl. quiet zones	Approx. height incl. digits	Typical use
80% (minimum)	0.264 mm	29.8 mm	20.7 mm	Small packs, only with high-quality printing
100% (nominal)	0.33 mm	37.3 mm	25.9 mm	Standard retail packaging
120%	0.396 mm	44.7 mm	31.1 mm	Labels from desktop and thermal printers, uneven surfaces
150%	0.495 mm	55.9 mm	38.9 mm	Larger boxes, rough board, flexo printing
200% (maximum)	0.66 mm	74.6 mm	51.9 mm	Large items, outer packaging

Figures are rounded and calculated from the nominal 37.29 × 25.93 mm. The 80% and 200% limits and the X-dimension values come from GS1; the in-between rows are simple multiplication.

Which size should you choose?

The minimum is a limit, not a target. A barcode at exactly 80% leaves no margin for ink spread, slightly fuzzy edges or a scanner that is not quite square to the pack. A commercial printer-maker's guide recommends 100–120% for reliable scanning, and that matches common practice: aim for 100% or a little above whenever the pack has room, and go down towards 80% only when you must and when the printing process is precise.

Bigger is not automatically better either. Above 200% you are outside the range GS1 specifies for retail scanning. In practice the bigger risk at large sizes is placement: a 75 mm wide barcode is much harder to keep away from edges and curves than a 37 mm one.

What about very small products?

For tiny packs there are two options. You can shrink an EAN-13 towards the 80% minimum, or you can use the shorter EAN-8 (GTIN-8). GS1 Netherlands only assigns an EAN-8 in specific cases, for example when the total printable area of the pack is under 80 cm², and points out that a reduced EAN-13 is often the simpler route. An EAN-8 is a different number, not a shortened EAN-13, so it has to be obtained as such; our article on EAN vs UPC vs GTIN explains the different lengths. If a product is too small for any barcode, the usual solution is to put the code on the outer packaging, a swing tag or a sticker on the bag it is sold in.

The X-dimension: the measurement that really matters

"Magnification" is the term most people know, but GS1 has deprecated it in its specifications in favour of the X-dimension: the width of the narrowest bar or space in the symbol, also called one module. Every other bar and space is a whole multiple of that width (one to four modules), so if you know the X-dimension you know the size of everything else.

• At 100%, X = 0.33 mm.
• At the 80% minimum, X = 0.264 mm.
• At the 200% maximum, X = 0.66 mm.

Thinking in X-dimension helps in two ways. First, it is what packaging printers and label software actually ask for, so quoting "X = 0.33 mm" avoids confusion about what "100%" refers to. Second, it explains the total width. An EAN-13 symbol is 95 modules wide. Add the light margins either side, as we read the GS1 General Specifications 11 modules on the left and 7 on the right, and you get 113 modules. Multiply 113 by 0.33 mm and you arrive at the 37.29 mm nominal width quoted above.

Why you should scale, not stretch

Magnification applies to the whole symbol. If you drag only the sides of a barcode in a design program, the bars get wider but the height stays the same, or the other way round. A stretched barcode may still scan on your phone, but it no longer matches the specification, and squashing it horizontally can push the X-dimension below 0.264 mm without you noticing. Always lock the aspect ratio (hold Shift in most design tools) and check the resulting width against the table.

Why you must not cut the bar height (truncation)

Designers often want to make a barcode less tall, because a full-height EAN takes up a lot of space on a slim pack. This is called truncation, and GS1 is direct about it: truncation "is not permitted within EAN/UPC symbology specifications" and it lowers scan rates.

The reason is how checkout scanners work. Many fixed scanners at tills project several laser or camera lines at different angles, so the cashier can swipe a product without carefully lining it up. A tall barcode gives those lines a wide target. A barcode cut to half its height only reads when the product is held at exactly the right angle, which means more rescans, more manual typing and more frustrated shop staff.

If the barcode does not fit, reduce its overall size (staying at or above 80%), move it to a larger panel, or rethink the layout. Do not chop off the bars. The same applies to cropping the human-readable digits so they overlap the bars, or placing a logo or text over any part of the symbol.

Quiet zones: how much white space does a barcode need?

The quiet zone is the blank, light-coloured area immediately left and right of the bars. A scanner uses it to recognise where the barcode starts and stops. If text, a border, a pattern or the edge of a label intrudes into that space, the scanner may not find the start of the code at all, or may read part of the surrounding design as an extra bar.

For EAN-13, the GS1 General Specifications, as we understand them, require 11 modules (11 × X) on the left and 7 modules on the right. UPC-A needs 9 modules on each side. Some guides simply quote "at least 11 modules" for EAN-13, which is the safe reading if you want one number to remember. Many barcode generators add a small ">" sign at the far right of the right quiet zone; it marks how much space should be kept clear, so do not crop it off or print over it. Always check the current edition of the GS1 General Specifications or ask your printer if you need the exact figure for a technical drawing.

Magnification	Left quiet zone (11X)	Right quiet zone (7X)
80%	2.9 mm	1.8 mm
100%	3.6 mm	2.3 mm
120%	4.4 mm	2.8 mm
150%	5.4 mm	3.5 mm
200%	7.3 mm	4.6 mm

A good barcode file already includes the quiet zones in its outer dimensions. Trouble starts when someone places it on the artwork and then trims the "empty" white edges to save space, or lets a background colour or photo run right up to the bars. Treat the whole rectangle, white margins included, as untouchable.

Which barcode colours scan, and why do red bars fail?

A scanner reads a barcode by measuring the contrast between dark bars and light spaces. Most retail scanners use red light. Anything that looks dark under red light works as a bar colour, and anything that looks light works as a background. That one fact explains almost every colour rule.

• Black bars on a white background are best. They give the highest contrast under any light.
• Bars must be dark and the background light. Reversed codes, with light bars on a dark background, cannot be read.
• Avoid red and reddish colours for the bars, including orange, pink and brown tones with a lot of red in them. Under red light those bars almost disappear.
• Red can work as a background, for the same reason: under red light it looks light. Test it before you commit, though, because shades vary.
• Bars should be one solid colour. Dark blue, dark green or very dark brown can work if black is not possible. Avoid bars built from several overlapping inks, screens or gradients.
• On transparent packaging, print an opaque white patch behind the bars. Do not rely on the product inside the pack as the background, because coloured liquids, dark contents or reflections will change what the scanner sees.

These rules follow GS1 UK's colour guide and GS1's implementation guide. The GS1 UK guide on barcode colours shows examples of combinations that pass and fail.

Colour combinations at a glance

Bars	Background	Result
Black	White	Best choice
Black	Yellow, light orange, light red	Usually works; test
Dark blue or dark green	White	Usually works
Dark brown	White	Can work if very dark; test
Red, orange, pink	White	Fails: bars vanish under red light
White	Black or dark colour	Fails: reversed contrast
Black	Dark blue, dark green, dark brown	Fails: not enough contrast
Any	Transparent film over contents	Unreliable: add a white underprint
Gold or silver (metallic)	Any	Risky: reflections confuse scanners

Kraft paper, textured stock and metallic films

Brown kraft boxes and bags are popular with small brands, and they are a frequent source of scanning trouble. The background is already mid-tone, so black bars have less contrast than on white, and the fibres make the edges of the bars ragged. The fix is simple: print or stick a white panel where the barcode goes, or use a white label. The same applies to dark-coloured boxes, coloured tissue, fabric labels and metallic or holographic foils, which reflect light unpredictably. A plain white rectangle under the code, including its quiet zones, solves most of these problems.

Where should you put the barcode on your packaging?

Good placement makes the difference between a code that scans on the first swipe and one that needs to be typed in. The firm rules are about avoiding damage and distortion:

• Never across an edge, fold, flap or seam. The bars get bent, split or hidden.
• Keep it away from areas that will be covered, such as under a closing flap, a price sticker, a security tag or a shrink-sleeve overlap.
• Stay clear of perforations, cut-outs, windows and heat seals.
• Check the orientation with your printer. On some printing presses, bars running in one direction print more sharply than bars running the other way, so the printer may ask you to rotate the code.

A common convention is to place the barcode on the back panel, towards the bottom right. This comes from GS1's placement guidance; treat it as a sensible default rather than a hard rule, and check the latest GS1 General Specifications if your buyer asks for exact positioning. What matters most is that the code is on a flat area that faces the scanner naturally when the product is put on the counter or held up.

Curved surfaces: bottles, jars, cans and tubes

On a round container, a barcode with vertical bars wraps around the curve, and the bars at the edges bend away from the scanner. GS1's guidance is that curved surfaces may need the barcode rotated so it stays scannable. In practice that often means turning it so the bars run around the container like rings (the barcode "lies on its side"), which keeps each bar flat along its length. The tighter the curve, and the larger the barcode, the more this matters. On a small vial even a rotated EAN-13 may be too much; that is one of the cases where the EAN-8 or a code on the outer carton is the answer.

Bags, pouches and soft packs

Flexible packs crease and stretch. Put the code on the flattest, most rigid area, often the middle of the back panel, away from gussets and the top seal. If the pack is filled with something lumpy (coffee beans, sweets, screws), test a filled sample, not a flat sheet: the bumps can distort the bars enough to stop a scan.

Clothing, textiles and unpackaged items

For clothing the barcode usually goes on a swing tag or a sticker on the polybag, not on the garment. Every size and colour needs its own code, so make sure the tag for the black medium carries the black medium's number. For unpackaged items such as ceramics or tools, a well-placed sticker on a flat underside works well, but check that it will not be peeled off with the price label.

Shipping cartons are a different case

Outer cartons and cases that hold several retail units are separate trade items. They are usually identified with a GTIN-14 in an ITF-14 or GS1-128 barcode, which has its own size and placement rules. The consumer unit inside must still carry its own EAN-13. Do not just enlarge your retail barcode and stick it on the carton, because a scan in the warehouse will then record one unit instead of a whole case.

Printing barcode labels yourself: resolution, labels and files

Most small sellers start with labels from a desktop laser printer or a thermal label printer. Both can produce good barcodes, but there is one technical trap that catches many people: printer resolution.

The dpi trap: why your printer cannot print "exactly 80%"

A printer can only make bars that are a whole number of dots wide. A 203 dpi printer, a common thermal label printer, has dots of about 0.125 mm. The X-dimension must therefore be 2 dots (0.250 mm), 3 dots (0.375 mm), 4 dots and so on. It cannot be 0.264 mm or 0.33 mm. GS1 notes that 200 and 300 dpi printers can only get to about 75.7–76.9% near the minimum, which is below the 80% floor. So on such a printer you should step up to the next whole-dot size, not down.

Printer resolution	Dots per module	X-dimension	Equivalent magnification	Verdict
203 dpi	2	0.250 mm	about 76%	Below the 80% minimum: avoid
203 dpi	3	0.375 mm	about 114%	Good default for thermal labels
300 dpi	3	0.254 mm	about 77%	Below the 80% minimum: avoid
300 dpi	4	0.339 mm	about 103%	Good default
600 dpi	7	0.296 mm	about 90%	Acceptable on small labels
600 dpi	8	0.339 mm	about 103%	Good default

Calculated from dot size (25.4 mm divided by the dpi). Good label software does this rounding for you if you tell it the printer's resolution; check the setting rather than assuming.

The same principle applies when a barcode image is placed in a document and printed "to fit". If the software scales the image by a small random factor, some bars end up one dot wider than others and the ratios between bars drift. Print at 100% scale ("actual size"), not "fit to page".

Vector files versus pixel images

For packaging artwork, use a vector barcode file (SVG, EPS or PDF) rather than a pixel image such as a JPEG or a low-resolution PNG. A vector file describes each bar as an exact shape, so it stays sharp at any size and the bar widths stay precise. A pixel image that is enlarged gets blurry edges, and one that is compressed as a JPEG gets grey fuzz around the bars, both of which reduce contrast and edge sharpness.

If you bought your codes from GTINcodes.com, you can download print-ready barcode images in SVG format for each of your codes from your account. Place the SVG in your design file, scale it proportionally to the size you have chosen, and leave its white margins intact; those margins are the quiet zones. If you print from a label program instead, you can usually type the 13 digits into its EAN-13 barcode tool and let it generate the symbol at the printer's native resolution.

Choosing labels and printers

• Direct thermal labels are cheap and need no ink, but they darken with heat and sunlight and fade over months. They are fine for shipping labels and short-lived stock, less so for products that sit on a shelf for a year.
• Thermal transfer labels use a ribbon and last much longer. They are a better choice for product labels.
• Laser printers on sheet labels produce crisp barcodes if the toner is fresh and the label stock is suited to laser printing. Check that sheets are not curling or smudging.
• Inkjet printers can work on coated label paper, but on uncoated or absorbent stock the ink spreads, which makes the bars fatter and the spaces narrower. If you must use inkjet, use a larger size (120% or more) and test carefully.
• Glossy or laminated labels can reflect the scanner's light. Matt white is the safest finish.

Briefing a packaging printer

If a print shop or packaging supplier is printing the barcode directly on boxes or pouches, give them the details in writing rather than relying on the artwork alone:

1. The full 13-digit number for each design, listed per variant, so they can check the artwork against it.
2. The barcode type (EAN-13) and your chosen X-dimension or magnification.
3. The bar colour (ideally 100% black, one ink, no screens) and the background (white or a white underprint).
4. A request to keep the quiet zones and full bar height, and not to resize or crop the barcode.
5. A request for a proof, and if possible a barcode verification report for the first run.

Experienced packaging printers may also adjust the bar widths slightly to compensate for ink spread on their press. That is normal and is something to let them handle. It is one more reason to send a clean vector file and the plain number instead of a flattened image.

How do you check that a barcode will scan?

There are two levels of checking: a quick functional test that anyone can do, and formal verification against the ISO standard.

Quick test with a phone or handheld scanner

1. Print one sample on the actual material, at the actual size, with the actual printer. A screen preview or an office print on plain paper does not tell you how a kraft box will behave.
2. Scan it with a barcode scanner app on your phone and, if you have one, a cheap USB handheld scanner. Both should read it immediately.
3. Compare the decoded digits with the number you intended. A barcode that scans but returns the wrong number is worse than one that does not scan.
4. Try it at an angle, from a little further away, and in dim light. If it only reads when held perfectly flat under bright light, something is marginal: usually size, contrast or the quiet zone.
5. For curved or flexible packs, test a filled, finished product, not a flat proof.

A successful phone scan is a good sign but not proof of quality. Phone cameras are very forgiving, and a code that a phone reads may still be graded poorly by a professional verifier or struggle on an older till scanner.

Formal verification: ISO/IEC 15416 grades

Barcode quality is formally measured with a verifier, a calibrated device that scans the code and grades it under ISO/IEC 15416 for linear barcodes such as EAN-13 (2D codes are graded under ISO/IEC 15415). The grade looks at contrast, edge sharpness, defects, quiet zones and how cleanly each bar decodes. GS1 sets the minimum grade required for each application.

Retailers are often said to ask for a grade of C (1.5) or better for retail barcodes, but requirements differ, so check the exact figure in your buyer's supplier manual. Some GS1 member organisations offer verification services; GS1 Spain, for example, offers a free one. Packaging printers often own a verifier too and can supply a report with the first print run. If you are only selling through your own webshop and marketplaces, a formal report is rarely required, but a clean test result still saves trouble in the warehouses that handle your stock.

Do you need a QR code or 2D barcode as well? (Sunrise 2027)

You may have read that 2D barcodes are "replacing" the classic EAN. The reality is more gradual. Sunrise 2027 is a GS1-led industry goal for retail checkout systems worldwide to be able to scan 2D barcodes, such as GS1 DataMatrix and QR codes carrying GS1 Digital Link, by the end of 2027. It is a readiness milestone, not a mandate. Amazon describes it the same way: "By the end of 2027, retail point-of-sale (POS) systems globally will support 2D barcodes." Its Sunrise 2027 page adds that serialisation is not required to be Sunrise-ready.

For now, a 2D code does not replace the EAN-13. GS1's support pages answer the question directly: "No, the GS1 QR Code provides extended packaging information only and needs to be used alongside an EAN or UPC barcode", and most checkout scanners cannot read it yet. Industry reporting from October 2026 expects 2D codes to sit next to EAN and UPC until retailer readiness reaches roughly 90–95%.

What this means for your artwork:

• Keep printing the EAN-13. It remains the code tills and marketplaces scan, and it is not going away in the near term.
• If you add a QR code, for a product page, instructions or a recycling message, place it separately from the EAN, with its own clear margin. Do not overlap or merge the two.
• Do not put an ordinary marketing QR code in place of the EAN. A QR code that links to your website does not carry a GTIN in a form a till understands.
• GS1 Digital Link encodes the GTIN in a web address inside a QR code and is normally tied to a resolver set up under the brand owner's GS1 licence. If your codes do not come from your own GS1 membership, it is doubtful whether you can use them in a GS1 Digital Link QR code, so plan any 2D project with GS1 or a specialist first.

Common barcode printing mistakes and how to fix them

Most failed scans come down to a handful of repeat problems. The table pairs each symptom with its likely cause and the fix.

Symptom	Likely cause	Fix
Does not scan at all	Quiet zone cut or covered; reversed or red bars	Restore white margins; use dark bars on a light background
Scans only when held perfectly still	Truncated height or size below 80%	Restore full height; increase to 100–120%
Scans as a different number	Wrong number in the artwork or a variant mix-up	Check digits against your product list before printing
Phone reads it, till does not	Low contrast, glossy finish or fuzzy edges	Matt white background, solid black bars, vector file
Thermal labels fail after a few months	Direct thermal labels faded	Switch to thermal transfer labels
Bars look fat and blurry	Ink spread on absorbent stock or an enlarged JPEG	Coated labels, vector file, larger size
Fails on bottles only	Bars bending round the curve	Rotate the code or reduce its size within limits
Fails on kraft or dark boxes	Not enough contrast	White label or white underprint behind the code
Warehouse records one unit per carton	Retail EAN used on the outer case	Identify cartons separately (GTIN-14 / ITF-14)

A worked example: a small candle brand

Take a candle seller with three scents in two jar sizes, sold on their own webshop and on a few marketplaces. That is six products, so six EAN-13 numbers. The jars are round, about 8 cm across, with a kraft-paper label wrapped around them.

• Size: the label has room for a code at about 100–110%. A 300 dpi thermal transfer printer at 4 dots per module gives X = 0.339 mm, about 103%, so the barcode area is roughly 38 × 27 mm.
• Colour: black bars printed straight onto kraft give poor contrast. The seller adds a white rectangle to the label design, sized to include the quiet zones.
• Placement: on an 8 cm jar a 38 mm barcode with vertical bars would wrap around a noticeable part of the curve. The seller rotates the code so the bars run horizontally, around the jar, and keeps it away from the label's overlap seam.
• Files: each scent and size gets its own SVG, named by the 13-digit number and the product name, so the right file goes on the right label.
• Test: one finished, filled jar per variant is scanned with a phone and a USB scanner, and the decoded numbers are checked against the product list before the full label run.

None of these steps costs much, but together they turn "it scanned on my screen" into a label that works at a packing station, in a marketplace warehouse and at a shop till.

Where the barcode is checked, and what it cannot fix

A well-printed barcode solves the physical part: the number gets from the pack into a computer. It does not change who the number is registered to. Codes bought from a reseller such as GTINcodes.com are valid EAN-13 numbers from GTINcodes' stock, issued once and registered to you in the GTINcodes register, which anyone can check on our EAN lookup page. They are not issued through a GS1 membership in your name, and in GS1's own database (Verified by GS1) such a code shows the original licence holder or no data, not your company. That is fine for many unbranded products, own webshops and marketplaces that ask for a valid, unique EAN. If you sell branded products on Amazon or bol.com, supply Zalando, or plan to sell through supermarkets and retail chains, GS1 membership is the better choice, because those channels check GS1 data. Our honest comparison of GS1 membership and reseller codes covers the trade-offs, and the guide to EAN codes for Amazon explains the GS1 brand check there. When you know which route suits you, you can see the codes and prices in our shops.

Barcode printing checklist

Run through this list before you approve artwork or send a label file to the printer.

The number

• 13 digits, with a valid check digit.
• One unique number per size, colour, scent, flavour and pack size.
• The digits on the artwork match your webshop, marketplace listings and stock system.

Size and shape

• Between 80% and 200% of nominal; aim for 100–120%. At 100% the symbol is about 37.29 × 25.93 mm and X = 0.33 mm; never below X = 0.264 mm.
• Scaled proportionally, never stretched or squashed.
• Full bar height: no truncation.
• On thermal or desktop printers, the X-dimension rounded up to whole printer dots (for example 3 dots at 203 dpi, 4 dots at 300 dpi).

Quiet zones and colours

• Clear light margins on both sides (about 11X on the left and 7X on the right for EAN-13), with nothing printed in them.
• Solid black or very dark bars on a white or light background.
• No red, orange, pink or reddish-brown bars, no reversed (light-on-dark) codes, no metallic inks.
• A white patch behind the code on kraft, dark, transparent or textured material.

Placement

• On a flat area, not across edges, folds, flaps, seams or perforations.
• Not covered by flaps, price stickers, tags or sleeve overlaps.
• Rotated on tightly curved bottles, jars and tubes if needed.
• Outer cartons identified separately from the retail units inside.

Files and testing

• Vector file (SVG, EPS or PDF), printed at actual size, not "fit to page".
• Thermal transfer or good-quality laser labels for products that sit on shelves.
• A finished sample scanned with a phone and a handheld scanner, at different angles, and the decoded digits compared with the intended number.
• A verification report (ISO/IEC 15416) if a retailer or distributor asks for one.
• Any QR code placed separately from the EAN-13, never instead of it.

For the background on these standards, GS1's Ten steps to barcode implementation covers size, colour and placement in one document, and GS1's change notice on magnification and X-dimension explains the move away from "percent". GS1 Netherlands' barcode support page gives the 80–200% range, and the GS1 page on EAN/UPC barcodes describes the symbology itself.