TurboPrint & PrintFab

Hi,

I'm desperately stuck on this so I'm reaching out here as a last resort.
Background: ~20 years personal, academic and professional pure Linux user. I'd prefer not having a Windows laptop/vm just for the
sake of printing since all my other photography workflows are Linux-based.

Problem:
2-3mm streaks mainly visibel on dark areas of print with smooth gradient. The artefacts are present on all three papers tried but are less prominent on the matt baryta and photorag baryta (this was printed in A4 so that might be a contributing factor)

Observation 1
Attempting to print from Darktable using "default" cups printer
Result: Extremely bad banding/streaking and unusable print quality

After this I made 6-8 test prints tweaking settings inbetween and performing nozzle checks, print head alignment, normal and deep cleaning cycles.
No improvements. While doing online research about the problem I discovered TurboPrint.

Observation 2
Attempting to print from Darktable using TurboPrint, default quality, variety of paper settings
Result: just as bad + unexpected green-ish colour-tint

Observation 3
Attempting to print from Darktable using TurboPrint, 1200dpi super quality setting (finest available) , variety of paper settings:
Result: Greatly reduced banding, BUT still what I'd call poor quality. still colour tint. I would not frame or display a print with these banding issues. The colour tint I consider secondary and I hope it would be fixed by the profiling service.
Observation 4
Print from Windows 10 with all the official canon drivers, highest available quality setting and a generic baryta paper profile (not available through turboprint)
Result: PERFECT 10/10 absolutely no trace of banding printing artefacts at all. No colour tint.
Setup details
Printer: Canon Imageprograf PRO-300 (purchased just over a year ago, and with just over 100 prints through it)
Inks: Original Canon PFI-300 purchased from canon
Papers tried:
- Fotospeed Platinum Baryta 300 A3+ (this is the one showed in the pictures)
- Fotospeed Matt Baryta 310 A3+
- Hahnemuhle photo rag baryta A4
OS: Ubuntu 24.04.1 LTS
Darktable version: 4.8.1
Turboprint: Studio XL 2.57-1 (02-SEP-2024) Demo version

Original images are too large to share.
Here are google drive links:
Tiff export of the raw image: https://drive.google.com/file/d/1arw0QQNLXYWy_0jHZWMStcAItUYvUb7P/view?usp=drive_link
Darktable+Turboprint with banding: https://photos.app.goo.gl/cn2UBhVkLrygNfvU6
Good print from windows+canon software https://photos.app.goo.gl/oUFGrGK6qZjvhhAH8


Any help or suggestions greatly appreciated. I wont hesitate to purchase a turboprint licence if there's even a chance this can be resolved.

Many thanks
Karl Svensson

Hello, thank you for the description and photos. The Canon PIXMA Pro-300 printer performs most of the quality relevant tasks within the printer firmware (conversion from RGB to the printer's multiple inks, halftoning, print head and paper movement control for minimized banding, etc.). TurboPrint mainly performs color management and sends a large color bitmap to the printer. According to our experience the print quality of TurboPrint and Canon's Windows driver is more or less identical, provided that a comparable print mode has been selected in the TurboPrint and Canon Windows driver settings.

To find out your current settings in Canon's Windows driver, can you please make screenshots? Another possibility to get access to all the settings is to send a printjob to a file from Windows. To reduce file size, you should reduce the print dimensions, then send by email to mail (at) zedonet (dot) de