intent=cmyk produces the following in the log file:

backend > profiles > setting format 'PDF/X-1a:2001' to 'PDF/X-1a:2001'

backend > profiles > using color intent 'CGATS001Compat-v2-micro.icc'

backend > profiles > using icc profiles 'sRGB-v4.icc,CGATS001Compat-v2-micro.icc'

backend > profiles > forcing pdf version 1.3, compression level 3, object compression disabled

backend > profiles > permitted colorspaces: rgb 'yes', cmyk 'yes'

colors > defining > supported models: gray 'true', rgb 'true', cmyk 'true', spot 'true'

transparencies > support > transparency is supported

I guess my question can be reduced to something very simple: is the result above acceptable for sending this pdf/x to a printer, given that we are printing only in BW/grayscale and that IngramSpark insist on pdf/x-1a?

Julian

On 5/18/25 06:46, jbf wrote:

I have to say that I remain confused about the intent statement. Let me
explain my confusion. Let's say my preamble says:

\setupbackend
[format=PDF/X-1a:2001,
intent=default]

(or I leave the intent blank), using the latest Context version
2025.04.28 14:29 LMTX, my log file tells me, amongst other things:

backend         > profiles > using color intent 'sRGB-v4.icc'

Hi Julian,

this is exactly what
https://www.pragma-ade.com/general/manuals/standards.pdf#page=3 (near
the end of the page) explictly states.

*but I thought that rgb and transparency were not appropriate for PDF/X.
Am I right about that?*

According to https://en.wikipedia.org/wiki/PDF/X, colors in PDF/X-1a
should be CMYK or solid ones (no color composing points of different
basic colors).

I think RBG and transparencies were adopted in later versions.

If I change intent to one of the color profiles listed on https://
wiki.contextgarden.net/Input_and_compilation/PDF/PDFX all of them cause
an error,

And what happens if you set "intent=cmyk" (from the same page as above)?

There is clearly something I do not understand about how I should
indicate the intent. If the items on the web page indicated above are
'pre-defined output intents', then why don't they work for me? Can
someone show me exactly how I should fill out the intent= part of
\setupbackend so that I get a valid PDF/X, or indeed can I simply ignore
it and just put in default?

"intent=cmyk" should add a CMYK color profile:
CGATS001Compat-v2-micro.icc
(https://github.com/saucecontrol/Compact-ICC-Profiles?tab=readme-ov-file#cmyk).

Anything I send to print is for grayscale or BW printing, not color.
What I currently do is to use an older 2022 version of ConTeXt where I
have the SWOP profile, and I think it is simply ignored. It certainly
does not cause compilation issues. but the more recent versions do.

According to
https://www.pragma-ade.com/general/manuals/standards.pdf#page=3, with
"intent=cmyk" there is also a gray scale profile added: sGrey-v4.icc
(https://github.com/saucecontrol/Compact-ICC-Profiles?tab=readme-ov-file#greyscale).

BTW, there might be a minor issue with this in the source. But I’m going
to ask in a new thread, since it is really independent.

I hope it helps,

Pablo
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