Printing services generally want CMYK. Nothing I can do about that. I'm looking at using drivethrucards.com to print some cards. They have a beta service which takes CMYK jpeg that I thought I would use. If that doesn't work I could use Scribus. I loaded it but I decided not to try when it loaded a dialog at an insane size for some reason. (It had to be at least 4 times the width of my screen.)

I'll give the imagemagik suggestion a try when I get a chance.

If anyone wants to see a prototype card:
https://social.freegamedev.net/photos/dulsi/image/6b4a87c2-eb26-4e0a-af26-e64f499a6a61

The text has been slightly altered since then and the pentagon around the 12 was cleaned up.

On Mon, 2020-11-16 at 01:33 +0000, Logan Brown wrote:
CMYK encoded jpegs are technically within spec ( https://www.itu.int/rec/T-REC-T.872-201206-I/en) but are exceedingly uncommon and support is pretty sporatic. Typically a JPEG contains RGB data encoded as YCbCr. If your application strictly requires CMYK data, you probably want to consider another file format.

Logan

From: Dennis Payne via WLUG <wlug@lists.wlug.org>
Sent: Sunday, November 15, 2020 8:22:01 PM
To: Worcester Linux Users' Group General Discussion <wlug@lists.wlug.org>
Cc: Dennis Payne <dulsi@identicalsoftware.com>
Subject: [WLUG] CMYK jpeg
 
Anybody know of an easy tool to convert an image into a CMYK color
space jpeg? I found an online site that works but would like to do it
on my machine. Searching has only found how to do it for tiff files.