: I need some help understanding DPI I have designed a custom deck of cards and I want to send my designs to print. It took me a few weeks to complete my designs using GIMP. I'm new to digital

@Jessie844

Just to complement jsbueno's answer. PPI is just a number except if you really need it.

The point you are missing is that you never, ever, mention a phisical dimension.

The total pixels you have 822x1122 make sense in 300 ppi using this operation:

822/300 = 2.74 inches.
1122/300 = 3.74 inches.

Your cards are measuring 2.74x3.74 inches.

Then the 300 ppi matches the requirements.

If you had not used the total pixels, but the phisical dimensions plus the 96ppi then you were in trouble.

96x2.74= 263 px
96x3.74= 359 px

But you are safe.

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@Nimeshi706

Any PPI requirement only makes sense if it is accompanied by a physical size, and if you're given a pixel size requirement then the PPI is irrelevant. As long as your pixel dimensions are correct then the PPI doesn't matter.

As I previously said here:


PPI is not an inherent property of an image. There is no such thing as a 300PPI image, or a 72PPI image. PPI is just a useful measurement for determining the print size of an image.

Which means PPI is completely irrelevant unless accompanied by physical dimensions. If someone says "Can we have that image in 300PPI?" they need to tell you a physical size in inches or centimetrs or whatever else, otherwise the question makes no sense.

A 100 × 100 pixel image saved at 300 PPI is exactly the same as a 100 × 100 pixel image saved at 72 PPI, or 10 PPI, or 1 PPI. They are even exactly the same if you print them at the same size.

The only times PPI is a useful measurement are...


You have a physical dimension requirement and you need to know how many pixels you need in your image.

Say you need a 6 × 4 inch image at 300 PPI, that allows you to calculate how big in pixels your image needs to be. 6 × 4 (inches) times 300 (PPI) is 1800 × 1200 — and there is your required size in pixels.
You have an image at a certain size in pixels, and you want to know how big you can print that image.

Say you have a 1800 × 1200 pixel image and you want to print it at 300 PPI. 1800 × 1200 (pixels) divided by 300 (PPI) is 6 × 4 — and that is your print size in inches.

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@Looi7658678

TL;DR: don't worry about the image settings for DPI – they are just a number. If you have it at the required number of pixels, everything is going to be fine.

The, often incorrectly required "DPI" – for "Dots per Inch" is only an indicative of how many printing dots per each linear inch your image will have. The number of pixels, on the other hand, is what conveys the actual image information.

To set the DPI on GIMP images, you can simply go to the Image->Print size... dialog box, and type in 300DPI, and see GIMP calculate the physical size the images will be printed at no loss.

See that if you have your image at 822x1122 pixels, and on the same dialog set it to "96DPI", the print size will be calculated to be larger than the physical card.

However, there are other issues at hand: if there is any text or drawings on the line (as opposed to photographic content), do not send them as jpg files – be sure to export your printing files as .png or .tiff.

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