Printer Ink Image

[grafdog1138]

So as I'm sure everyone understands, printers don't print white. They just leave white areas transparent, since they assume that the paper is white. And all colors which contain white are only printed with a certain amount of ink, again assuming that the white paper will "correct" the color so that it prints the same way it displays in the file.

So my question is, can someone walk me through how I can turn all the "whiteness" in an image into transparency, in effect mimicking this printing behavior? I hope this question makes sense, I can clarify if need be.

Thank you!

[Blighty]

(04-23-2019, 06:17 PM)grafdog1138 Wrote: how I can turn all the "whiteness" in an image into transparency

Use Colors > Color to Alpha and accept the default white.

Color to Alpha has to requirements:
1) there must be an alpha channel Layer > Transparency > Add Alpha Channel
2) Mode must be rgb Image > Mode > RGB

[grafdog1138]

(04-23-2019, 06:42 PM)Blighty Wrote:

(04-23-2019, 06:17 PM)grafdog1138 Wrote: how I can turn all the "whiteness" in an image into transparency

Use Colors > Color to Alpha and accept the default white.

Color to Alpha has to requirements:
1) there must be an alpha channel Layer > Transparency > Add Alpha Channel
2) Mode must be rgb Image > Mode > RGB

Worked perfectly! Thanks so much!

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(04-23-2019, 07:40 PM)grafdog1138 Wrote:

(04-23-2019, 06:42 PM)Blighty Wrote:

(04-23-2019, 06:17 PM)grafdog1138 Wrote: how I can turn all the "whiteness" in an image into transparency

Use Colors > Color to Alpha and accept the default white.

Color to Alpha has to requirements:
1) there must be an alpha channel Layer > Transparency > Add Alpha Channel
2) Mode must be rgb Image > Mode > RGB

Worked perfectly! Thanks so much!

Ok just one more problem: when I export to either jpg or png, the transparency isn't preserved, it just reverts to the way it was?

[Blighty]

(04-23-2019, 07:40 PM)grafdog1138 Wrote: Ok just one more problem: when I export to either jpg or png, the transparency isn't preserved, it just reverts to the way it was?

jpg does not support transparency. The transparency will be converted to the background colour set in Gimp (usually white).

png does support transparency, works fine in Gimp. But some websites, image viewers, etc convert transparency to some colour, usually black or white. Problem might be there.

Remember to Save as xcf, as this preserves layers etc.

[grafdog1138]

(04-23-2019, 08:06 PM)Blighty Wrote:

(04-23-2019, 07:40 PM)grafdog1138 Wrote: Ok just one more problem: when I export to either jpg or png, the transparency isn't preserved, it just reverts to the way it was?

jpg does not support transparency. The transparency will be converted to the background colour set in Gimp (usually white).

png does support transparency, works fine in Gimp. But some websites, image viewers, etc convert transparency to some colour, usually black or white. Problem might be there.

Remember to Save as xcf, as this preserves layers etc.

Ok right, I misunderstood jpg.

My problem was that when I was exporting to png, the transparency that I introduced using the steps above was lost, and the image was just like it was before my edits. But I think I figured it out: you have to uncheck the "save background color" box.