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Whenever I export to .png it is a HUGE file... How do I export it into centimeters?
(12-02-2019, 01:35 AM)joeygoldman Wrote: [ -> ]Whenever I export to .png it is a HUGE file... How do I export it into centimeters?

Bitmap images have sizes in pixels. You need to create the image at the correct size.

For example, an image has a size of 1200 x 1200 pixels. The resolution is set to 300dpi.
Print size will be
1200/300 = 4 inches.

You can see the print size by using Image > Print Size.
You can change the width or height. Resolution will change accordingly.
Or you can change the resolution. Width and height will change accordingly.
The image size in pixels does not change.

You need 300dpi for a good quality print.
I changed the print size to cm and its still coming out huge. 20974x20974!
Gimp will not change the size in pixels when you change the print size. Print size and print definition are just metadata, they can be changed at will. Changing the size in pixels is somewhat final (once you have scaled down, scaling up again will give you a blurry image).

Which doesn't mean that in your case the size in pixels could be much bigger than what you really need. At 300PPI (~120 pixels/cm) your current image is 177x177cm. If you intend to print is at a much smaller size, for instance 20x20cm (7.87 inches) then at 300PPI you only need an image which is 300*7.87=2362pixels. So you can use Image>Scale image to downscale your image. And even if you need a physically large image, the larger the image, the further away people are, so you can reduce the resolution (billboards are a 10PPI or less...). In practice you rarely need to be bigger than 12Mpix, so you could downscale your image to 4000x4000.