How to Choose Common Poster Sizes in Taiwan: A0, 8K, and 4K Print Specs Explained

Here is the most direct answer: posters in Taiwan most commonly use two sizing systems. One is the international A series standard (A

・0, A

・1, A

・2), and the other is the traditional printing K-size system (4K, 8K, Ju-quan, Ju half-sheet)

These two systems are often discussed together, but they come from different origins

The A series is the ISO 216 international standard. Its defining feature is a fixed aspect ratio of 1:sqrt(2), about 1:

・1

・414. When folded in half, the proportion stays the same, so A0 folded in half becomes A

・1, A1 folded in half becomes A2, and the same tall, narrow proportion continues all the way down

Common specs:

・A0: 841 x 1189 mm. Visually, it feels about like putting a single mattress on the wall. It is a mainstay for exhibition key visuals and large event posters

・A1: 594 x 841 mm. The most common size for storefront standees, election signage, and course recruitment posters

・A2: 420 x 594 mm. A standard everyday size for in-store posting, lecture announcements, and community bulletin boards

The K-size system is the old language of Taiwan's printing houses, derived from how a full sheet of paper is cut

If a full sheet is cut into a certain number of equal parts, that number becomes the K size: one cut in half is a half-sheet, another cut is 4K, and another is 8K

Here is a key concept that trips up many designers: the actual dimensions of a K size change depending on the parent sheet size

The two most common parent sheet sizes in Taiwan are Ju-ban, about 25 x 35 inches, and 46-ban, also called Ju-bei, about 31 x 43 inches

So when someone says "4K," Ju 4K is about 27 x

・39.5 cm, while 46 4K, or Ju-bei 4K, is about

・39.5 x

・54.5 cm. That is a very big difference

Seeing "4K" on a quote and applying a size directly is one of the easiest ways to make a costly mistake

Many clients ask me, "Why do some print shops talk about A1, while others talk about Ju half-sheet?"

The answer depends on the equipment and the use case

Digital output and large-format output, such as inkjet printing, almost always use the A series for sizing because the equipment works in metric millimeters. Say A0 or A1 and everyone understands immediately

Traditional offset printing, on the other hand, usually uses K sizes because costs are calculated from the full sheet, and the K size directly reflects how efficiently the paper can be used on press

My advice is simple:

・For small quantities, large sizes, and fast turnaround, usually 1 to 50 sheets, use large-format output and communicate in A series dimensions

・For large quantities where unit cost matters, usually 500 sheets or more, use offset printing, communicate in K sizes, and always confirm whether the shop is using Ju-ban or 46-ban

Here is a common real-world example: a client wants to print 1,000 A2 posters. If the job is imposed on Ju-ban paper, one full Ju sheet can fit four layouts close to A2, with almost no paper waste. But if the size lands on an awkward number, a full sheet might fit only three posters, with the rest becoming scrap, and the unit price rises immediately

That is why confirming the size before quoting will always save more money than quoting first and changing the size later

Getting the size right is not enough. If these three specs are not set correctly before sending the file, the printed result can still be a disaster

The first is bleed

If your design has color or imagery extending all the way to the edge, you need 3 mm of bleed on all four sides

That means an A1 poster, 594 x 841 mm, should be prepared as a final artwork size of 600 x 847 mm. The extra area will be trimmed off during cutting

Why is this necessary? Because cutting blades can never be 100% precise. Bleed gives mechanical tolerance some room. Without it, the finished edges may show a thin white line, which immediately makes the piece look cheap

The second is resolution

For posters viewed up close, such as storefront, window, and anything A2 or smaller, 300 dpi is recommended. This is the standard sharpness for printed materials

But here is a concept often misunderstood in the industry: resolution should be determined by viewing distance, not by the idea that higher is always better

For large outdoor banners or exhibition backdrops viewed from several meters away, 100 to 150 dpi is more than enough. Forcing them to 300 dpi only makes files so large that they are hard to transfer and slows down output

The third is color mode

For print, always use CMYK. Do not send RGB files

Screens emit light in RGB, while printing uses CMYK ink. Their color gamuts are different

The most common disappointment is seeing saturated bright blues or fluorescent greens on screen, then watching them become noticeably darker and muddier after conversion to CMYK print

The correct approach is to set the document to CMYK at the design stage so what you see is closer to what you get, instead of converting only after the artwork is finished and then being shocked by a bad print result

Also, text must always be outlined, meaning converted to outlines or curves. Otherwise, if the print shop does not have your font, the layout may shift

Once the size and file are correct, the final stretch is paper stock and post-processing. This directly determines the poster's perceived quality

Here are several pairing principles I often use:

・Indoor posting and short-term events: use 150 to 200 lb coated paper or matte coated paper. The cost is low, output is fast, and it is the best value for posters that will be replaced after one or two weeks

・Storefront standees or displays that need to stand upright: mount directly on 5 mm or 10 mm KT board, also known as foam board, or PP board so it can stay standing

・High-quality key visuals and brand image walls: consider matte lamination to reduce scratches and reflections, or spot UV to make visual layers stand out

・Outdoor use or exposure to water: use waterproof PP synthetic paper or outdoor banner material. Coated paper is ruined as soon as it gets rained on

One practical reminder: if a poster needs to be rolled for shipping or long-term storage, do not choose paper that is too thin. Anything below 150 lb is more likely to keep crease marks and wavy edges after rolling, and it will not lie flat when opened

These choices of paper stock and finishing are actually the key to whether a poster looks expensive. Size is only the entry ticket

・Taiwan uses two poster size systems: the A series, which is metric and favored for digital output, and K sizes, the language of traditional offset printing. First, make sure you know which system the other party is talking about

・K-size dimensions change with the parent sheet. The same "4K" can differ by nearly double between Ju-ban and 46-ban, so always confirm the sheet type before quoting

・For full-bleed designs, leave 3 mm of bleed on all four sides. An A1 final artwork file should be 600 x 847 mm. Without bleed, cutting can reveal white edges

・Resolution depends on viewing distance: 300 dpi for close viewing, and 100 to 150 dpi is enough for large backdrops viewed from farther away. Higher is not always better

・For print, always use CMYK and always outline text. Bright RGB colors become muddy in print, and missing fonts can break the layout

What actually causes poster problems is rarely design ability. More often, it is that the specs were not aligned before work began

My recommendation is to turn "size, bleed, resolution, color mode, and paper stock" into a five-point prepress checklist. Designers should run through it before handing off files, and it can prevent most reprints

For design teams adopting AI tools, these five points are exactly where templates and automated checks are most useful: upload the file and automatically verify whether the bleed is sufficient, whether the file is CMYK, and whether the resolution is correct, freeing people to focus on creative work

For clients, the easiest approach is to work with a vendor that can handle everything from size recommendations and file checks to printing and finishing, instead of finding separate providers for design, printing, and mounting. Specs are most easily lost when they are passed around between parties. The core value of the integrated service MINDS Printing provides as MINDS, a mid-to-high-end fully customized commercial printing provider, is exactly this: reducing the communication cost of specifications to a minimum, so you can avoid one more reprint