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Can't grasp relationship between image resolution and printer DPI - Printable Version

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Can't grasp relationship between image resolution and printer DPI - 3d1l - 04-02-2022

Hello there,

I want to create an image that will be printed in a 8.5" x 11" sheet of paper. My printer (an entry level color laser printer), can print at 600 DPI. I want to print the entire image to occupy the whole paper looking sharp and crisp (as far as my printer allows it). If I set the size of the image to 8.5" x 11" with 600 DPI, the result is a huge image that is difficult to manipulate since I'm going to be using lot of warp tool and filters.

So how should I proceed?

Should I forget about the DPI setting until I finish creating the image?

Again the image I'm creating is not to be seen on a screen but to be printed.


RE: Can't grasp relationship between image resolution and printer DPI - rich2005 - 04-02-2022

Gimp images are width x height in pixels and to convert, it is units (in your case inches) x pixels-per-inch (inch=unit) usually abbreviated to [b]ppi[/i]

For quality, the rule of thumb for photo quality is 300 ppi Unless it is a scan of say a postage stamp, 600 ppi is a bit over the top. It is for the user to decide.

There is a standard 300 ppi US letter (8.5" x 11") in File > New in the dropdown Template menu.

Make with a smaller ppi image for printing ? It all depends on the image. The printer software will do the scaling but depending on the degree of scaling the degradation can be noticeable, scaling up generally leads to loss of sharpness as pixels are interpolated. You can do the scaling yourself, Image > Scale Image , use the best interpolation, 'NoHalo' and see if the result is acceptable. Print off sample pages at different resolutions, small text is a good marker.

There is a discourse about resolutions here: https://www.gimp-forum.net/Thread-Image-size-in-Gimp

Edit: As usual, I do not think I am answering the question Wink

The printer dot-per-inch (dpi) is the amount the printer spits out toner (or ink) onto the paper.

If your image consists of a 1" x 1" square, then the printer (depends of printer quality settings) fills that with 600 x 600 = 360000 spots of toner.

Your image on the other hand is made of pixels and depending on pixels-per-inch (ppi) that number can vary 50 ppi 1" x 1" = 2500 pixels or 200 ppi = 40000 pixels . The printer still considers that 1" x 1" and will fill those pixels with 600 x 600 spots of toner (600 dpi)


RE: Can't grasp relationship between image resolution and printer DPI - 3d1l - 04-02-2022

@rich2005 Thanks, yes I do understand those concepts. The image I'm working with is not a photo or something like that, is an image that I'm creating from scratch. Krita could be a better tool, perhaps, but I know more about GIMP so I'm gonna stick with it. My question was more in the sense if I should specify a lower DPI in the image setting so I can work with it because if I set 8.5" x 11" (and that's the real size of the final image and print), with 600 DPI, it is so huge that is hard to work with it on my computer. At the end I want to print it with the maximum amount of "resolution" that my printer allows and that's 600 DPI, this is something that will be look at reading distance. Or, it could be that if I want to print that size at 600 DPI, that's the way it is and what I need to do is to replace my computer with one with higher specs.


RE: Can't grasp relationship between image resolution and printer DPI - rich2005 - 04-02-2022

Not a photograph, a graphic design and going to be printed on your home laser printer.

I would use the Gimp default 300 ppi US letter template. You might be able to get away with less (ppi), all depends on the graphic.

A little bit here: http://resources.printhandbook.com/pages/dpi-for-printing.php

edit: I do not think you have got idea of the printer dpi resolution. My inkjet has (had to look it up) Maximum native print resolution 6,000x1,200dpi That does not mean that I would use that setting for a new image. For a photograph on good quality photo paper I use 300 ppi. For printing on other paper, I might still use 300 ppi but really a bit of a waste of ink.


RE: Can't grasp relationship between image resolution and printer DPI - Ofnuts - 04-03-2022

(04-02-2022, 06:11 PM)rich2005 Wrote: Not a photograph, a graphic design and going to be printed on your home laser printer.

I would use the Gimp default 300 ppi US letter template. You might be able to get away with less (ppi), all depends on the graphic.

A little bit here: http://resources.printhandbook.com/pages/dpi-for-printing.php

edit: I do not think you have got idea of the printer dpi resolution. My inkjet has (had to look it up)  Maximum native print resolution 6,000x1,200dpi   That does not mean that I would use that setting for a new image. For a photograph on good quality photo paper I use 300 ppi. For printing on other paper, I might still use 300 ppi but really a bit of a waste of ink.

And the "dots" are individual droplets of ink, so the color or the corresponding cartridge. One pixel in your image is actually rendered by a pattern of individual color dots, so pixels and dots are different things.