Good to know
What DPI do you need for large format printing?
The short answer
Most large format printing needs 100 to 150 pixels per inch at the finished size, not the 300 used for brochures and business cards. What sets the number is how far away people stand. A poster read up close wants more, a banner seen across a room needs less, and a billboard needs very little.
DPI and PPI, and which one is yours
DPI, dots per inch, is how many dots of ink a printer lays down in an inch. It belongs to the printer. You will see numbers such as 600 or 1200, and they are not something you set in your file.
PPI, pixels per inch, is how many pixels of your picture land in each inch of the finished print. It belongs to your file, and it is what people nearly always mean when they ask for "a 150 DPI file".
The two get used as one word. On this page, the number that matters is pixels per inch at the size the piece will be printed.
How far away sets the number
Your eye can only make out so much detail, and less the further back you stand. A print that has to hold up at arm's length needs many more pixels in each inch than one seen from across a parking lot.
What is in the picture matters as well. A photograph with fine detail shows softness sooner than big lettering and flat color.
These are the common targets across the trade, at full size. They are rules of thumb, not a specification for your job.
| What it is | Usually seen from | Pixels per inch |
|---|---|---|
| Brochures, cards, anything held in the hand | About a foot | 300 |
| Posters and photo prints read up close | 2 to 4 feet | 150 to 300 |
| Banner stands, indoor banners, and backdrops | 5 to 10 feet | 100 to 150 |
| Outdoor banners and building signs | 15 feet or more | 50 to 100 |
| Billboards | Across a road | 10 to 30 |
Is your picture big enough?
Divide the picture's width in pixels by the width of the print in inches. The answer is its pixels per inch at that size.
A photo 6000 pixels wide, printed 40 inches wide, is 150 pixels per inch. Printed 60 inches wide, the same photo is 100.
Your computer shows a picture's size in pixels in the file's details. Here is what some common sizes need.
| Print size | At 100 per inch | At 150 per inch |
|---|---|---|
| A3, 11.7 x 16.5 in | 1169 x 1654 | 1754 x 2480 |
| Poster, 18 x 24 in | 1800 x 2400 | 2700 x 3600 |
| Poster, 24 x 36 in | 2400 x 3600 | 3600 x 5400 |
| Banner stand, 33 x 80 in | 3300 x 8000 | 4950 x 12000 |
| Banner, 4 x 4 ft | 4800 x 4800 | 7200 x 7200 |
| Banner, 3 x 6 ft | 3600 x 7200 | 5400 x 10800 |
| Banner, 4 x 8 ft | 4800 x 9600 | 7200 x 14400 |
Will a phone photo work?
Often, yes. A 12-megapixel photo is about 4000 x 3000 pixels. That is 150 pixels per inch on a print 27 x 20 inches, and 100 on one 40 x 30 inches.
Two things spoil it. Cropping in tightly throws pixels away. And a photo that was sent in a text message or saved from social media has usually been shrunk on the way. Use the original file.
What does not make a small picture bigger
Typing a larger number into the resolution box does not add detail. The program invents the missing pixels by guessing, and the print comes out soft.
A logo saved from a website is the usual case. It may be only a few hundred pixels wide, which is fine on a screen and far too small for a sign.
Logos and lettering should be vector artwork instead. Vector has no pixels, so it prints sharp at any size and the question of resolution goes away.
Building the file at a smaller scale
A banner at full size and 150 pixels per inch is a very large file. Designers often build big pieces at half or quarter size to keep the file workable.
The resolution scales with it. A file at quarter size and 400 pixels per inch is 100 at full size. Say what scale you used when you send it.
Questions
More about resolution
Don't see yours? Call 419.224.8747 and ask a person.
EXCELLENT4.9 from 58 Google reviews, rated 4.9 out of 5. Opens our Google Business profile in a new tabIs 72 DPI enough for a banner?
It can be. At full size, 72 pixels per inch looks fine on a banner seen from across a lot, and soft on one read at arm's length. A file that is 72 because it came from a website is usually also small in inches, and that is the real problem.
Do I need 300 DPI for a poster?
Only when it will be looked at closely, such as a photo print or a piece of artwork. For most posters, 150 pixels per inch at full size looks sharp from a normal reading distance.
What is the best DPI for printing large photos?
Aim for 150 pixels per inch at the finished size, and more if people will stand right in front of it. Below 100, a photograph starts to look soft up close.
How many pixels is A3 at 150 DPI?
1754 x 2480 pixels. A3 is 11.7 x 16.5 inches.
How many pixels do I need for a 4 x 4 foot banner?
4800 x 4800 pixels gives 100 pixels per inch, which suits a banner seen from several feet away. 7200 x 7200 gives 150.
Does a higher DPI always look better?
No. Past what the eye can make out from where people stand, more pixels only make the file bigger and slower to work with.
My printer says 1200 DPI. Does my file need to be 1200?
No. That number is how finely the printer places ink. Your file needs far fewer pixels per inch than the printer has dots.
My logo goes blurry when it is enlarged. What can I do?
Find the vector version, usually an AI, EPS, or SVG file from whoever designed it. If there isn't one, our design team can rebuild the logo.
Design ServicesCan you check my file before I order?
Yes. Send it and tell us the size you need. We'll look at it, and you'll see a proof before anything prints.
Also worth a look
Not sure your picture is big enough?
Send it with the size you need. We'll check it, and you'll see a proof before anything prints.