Discussion on linux support for the epson sc-P900, drivers, print quality

[taco-fever]

I got my hands on an epson sc-P900, and I'm working exclusively on linux, with darktable. And I'm a bit lost in how to proceed to actually use my printer on linux.

I want to use it mostly for photography print on fine art papers. I also want to be able to calibrate the printer and get accurate colours relatively to my calibrated monitor. I'm not by any mean a color expert, but I really like to understand how things work, and from the artistic point of view, more way to control the printer is also more way to better convey the emotions in a photograph.

As a my participation to the community, I tried to gather in this post all information I got about linux use of the P900 !

Here are the options I came across:​

The gutenprint driver, turboprint, and Airprint and/or IPP. I also head somewhere that espon linux driver have undocumented support for the P900, but I have no more info on that.

TURBOPRINT:​

Support the P900, and icc profiles. Some people complain about the software stability. It seems to be a high quality driver, but I have not seen quantitative information on that.
It is often said that Turboprint is cheap, but for this printer, Turboprint driver is quite expensive, as you have to add the studio XL option ( 179,95€ in total), and I would much rather not having to pay that much just to use the printer, if I don't need to. It is great that turboprint exist, but personnally, I would rather spend my money on paper and ink for the open source community.

GUTENPRINT:​

Support icc profiles, from what I read, by including them in the file.
Gutenprint current support for the P900 is incomplete (based on the P800 which has a different resolution, number of ink, and matte/glossy black handling), here is a summary of the discussions I came accross in the gimp-print mailing list. It seems that quite a few people would be interested in gutenprint to support the P900. I hope these information can help someone along he path:

• 2021-10-25 [Gimp-print-devel] P700 and P900 full channel support

discussion on how the printer select matte /glossy ink and violet channel.
Seems rather technical, as it involves reverse engeneering the official driver

• 2021-10-31: [Gimp-print-devel] was - P700 and P900 full channel support

discussion on ESCP/R vs escp/2
P900 seems to support escp/2, but the official driver uses escp/R

code for violet new ink, and matte black ink

Air print vs gutenprint discussion

• 2021-09-30 Epson P900 support?

In particular, any new escp2 commands ?

if you genuinely do need Gutenprint's feature set, adding support will take either direct physical access or someone willing to do the necessary legwork, and will require expending a decent amount of ink before the quality will be considered usable.

• 2023-03-30 [Gimp-print-devel] Epson SC-P900 Support

If that's not good enough, and you need Gutenprint's feature set, I'd
expect getting the printer working will be straightforward (specs imply
ESC/P2, 10 ink channels, 180 nozzles per), but in that ink set there's a
new violet ink that would need to be added to gutenprint, and of course
a decent amount of ink would need to be expended to tune the overall
output until it's of sufficient quality.

But as an example, when I added in the Epson SL-D700 (roll-fed, 6-color
inkset) about two years ago, I produced over 100 6x8" prints before the
print quality was considered "good enough" for client -- and there was
still a lot of work remaining for the remaining quality+paper
combinations.

• 2022-01-02 [Gimp-print-devel] Epson SC-P900

The main differences are a new ink set and support for a higher
resolution mode.

If that appears to mostly work, then you'll need to create a set of XML
data files for the inkset and underlying model, this commit (for the
SL-D700) shows what's needed:

597efe256b6e0ea8ffc48d780371cd67983a4e4c

Maybe prefer airprint ?

• 2022-12-21 p700 packet parsing

AIRPRINT/IPP:​

I haven't been able to find much information on how to use airprint with the P900, what set of features it supports. I haven't found anything on calibration and color management, print resolution/quality.

My questions:​

Driver quality comparison:​

I'm trying to get an understanding on how these different ways of using the printer impact the quality of prints, and how much control over the printer they offer.

Correct me if I'm wrong, but from what I understood now, gutenprint and turboprint are actual drivers, controlling directly the printing heads through escp commands. They both take rgb images and perform the required dithering process, and offer high resolution printing (through waving). They both offer a option to print without color management so calibration is possible.

I could not find much documentation on how airprint is actually implemented by epson, but I'm guessing that, as opposed to the other two, the driver is embed in the printer itself, and the printer is doing the processing to convert the rgb image to printer commands. I guess it implies less control, and less quality because printer has less compute power than a computer. Otherwise, epson wouldn't provide a windows driver.

But I haven't seen any "real" comparative test between drivers anywhere, apart these resolution test by Ink stained Fingers (thanks !!) here on the forum. So I have no idea what the difference would make on print quality in real life. Any references on that ?

New color support in gutenprint:​

A side questions, probably naive, for printer driver specialists. I don't quite get why, in gutenprint for example, it seems so complicated to add a new ink (apart from finding how to speak to the printer).
It seems to me that it would be the role of a spectrophotometer to solve these kind of problem...?
Isn't any "automated"/direct way, to find parameter for the printer to avoid days of tweaking, and 100 sheet of paper ?
What is the actual relative importance of parameter tweaking/icc profile calibration in the quality of color reproduction?

I'm guessing that calibration with spectro is when printer already behaves quite close to the "optimal" color reproduction. Calibration software, like argyll, are working in rgb for the P900, which is quite high level compared to printer inks. And that the dithering methods and parameters about how and how much the driver lay the inks is much more important. Do someone has more knowledge/references on that?

What to do in practice?​

Considering the current gutenprint support of the P900, the use of airprint it advised by a gutenprint developer. Has anyone experienced printing through airprint on linux with the P900 ?
In general, what would be your advice to get my printer working, considering my needs ?

Anyway, thanks for those fo you that went through this super long post, a big thanks to the whole community here, to share so much tests and information about printing. It is really refreshing !

 

[taco-fever]

There is also this blog post by Robert Elder:
https://blog.robertelder.org/linux-printer-debugging/
who did quite some fighting with cups, managed to print hello world, but ended up to use turboprint instead.