03-15-2018, 06:35 PM
Two things to note:
1. Gimp uses sizes in pixels, not real world sizes like mm.
2. A 90mm circular image is actually a square 90x90mm. The portions outside of the circle are transparent.
Both your square and circle will be the same size, 90x90mm.
For a good quality print you need 300 dpi, or 11.81 pixels per mm.
90 x 11.81 = 1063pixels. ie an image 1063 x 1063 pixels.
Gimp can do these calculations for you. Go to File>New and set the width and height to 90mm. In the advanced section set the resolution to 300 dpi. You will see on that screen that the image size has been set to 1063 pixels.
1. Gimp uses sizes in pixels, not real world sizes like mm.
2. A 90mm circular image is actually a square 90x90mm. The portions outside of the circle are transparent.
Both your square and circle will be the same size, 90x90mm.
For a good quality print you need 300 dpi, or 11.81 pixels per mm.
90 x 11.81 = 1063pixels. ie an image 1063 x 1063 pixels.
Gimp can do these calculations for you. Go to File>New and set the width and height to 90mm. In the advanced section set the resolution to 300 dpi. You will see on that screen that the image size has been set to 1063 pixels.