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Color-safe workflow for print artwork?

Robert 2 years ago updated by Vitaly Ovchinnikov 2 years ago 9

I’m wondering what the recommended workflow for the creation of print artwork with CMYK color space might be. Specifically I am trying to save a rendered book mockup with transparency that shall be used in an InDesign document. PNG is obviously the only choice, but PNG doesn’t support CMYK. Moreover the PNGs generated by Boxshot don’t include a color profile. Is there any color management in Boxshot? I wouldn’t mind converting the (CMYK) original cover art to (e.g.) AdobeRGB, then go for rendering and then convert the rendered image back to CMYK. But what is Boxshot doing with embedded color profiles? Silently throwing them away, rendering the image correctly and saving without embedded profile? Or is there any color conversion going on? (If yes, please don’t let it be sRGB!)
Please help, the color thing is a real show-stopper for professional print production. :-/

Some time ago I had your same problem. To be sure that the changes were reduced to the minimum acceptable I proceeded like this: 
1) with Photoshop I opened the png file generated by Boxshot to see resolution and size; 
2) always with Photoshop I opened the Illustrator file preserving its color profile; 
3) Finally I overwrote the Boxshot png file with the same characteristics with good results. 
I hope this information can help you

If I understand you correctly, you open the PNG in Photoshop and then change the color mode to CMYK (which will set the default profile configured in PS)? And do you use a CMYK oder RGB image for rendering in Boxshot?

No. I opened the png only to see resolution and measures. BS needs a png that can be in RGB only. I opened the Illustrator file with Photoshop just to have control over color profile and transformation from cmyk to rgb. But consider that it's impossible to have same colors both in cmyk and rgb. Hope this helps.

Under review

Internally Boxshot performs rendering in sRGB, so for all the input files it converts their color profiles to sRGB, then renders a frame and saves it with sRGB profile. Sometimes it is assumed to be sRGB, sometimes sRGB profile is embedded, depending on the format.


This "non-linear" processing is not the best thing we can do, so we're slowly moving to the linear one. For instance Owlet was switched to it recently. The difference is that all the input files are converted to linear space, not sRGB and all the rendering happens there. Then the result is converted back to sRGB.


I understand that this might not be the behaviour that you expect, so let's discuss the best option? Will it help if we offer a list of color spaces to convert to? Or maybe you just need a way to save a linear-space output? For instance in Owlet you can export to EXR or PSD and get a linear floating-point image that you can convert to whatever color space you want without losing any details. Assuming we have a linear-processed buffer of floating point RGB colors, what can we do to export it the best way?


Btw, Boxshot supports transparency in PNG, TIFF and PSD output formats.

Thanks for the clarifications!

As I understand it – but I am not an expert in color management – conversion to sRGB (and back) will result in a loss of color information. So the mentioned linear processing might be the best way to go. Is there any schedule for the implementation of linear processing?


I am working with image files with either AdobeRGB or ISO Coated v2 300% (CMYK) color profiles. Cover images for books for example are CMYK (but get exported as JPG with embedded AdobeRGB profile for web usage without any obvious color differences). I am using Boxshot for both web graphics and printed material (which requires conversion to CMYK). That said, I wouldn’t mind converting color spaces back and forth upfront, as long as someone tells me, which workflow is the best. It’s not about 100% color accuracy, but if I simply use CMYK images for rendering, the result looks terrible – maybe just because the correct color profile isn’t embedded. 


A list of available color spaces would definitely be a big plus. (Considering that Boxshot Professional is marketed with "Rendering to print" functionality, I would even say, it’s a requirement.)

Can you explain, how to export as PSD? I can only save as BMP, EXR, HDR, JPG, PNG, and TIFF. Am I missing something?

I probably just figured out, how to get the best results when using CMYK as a source:


1. Render as TIFF

2. Open in Photoshop

3. Convert to desired target profile

4. Save in Photoshop


The resulting image can then be used e.g. in InDesign, including transparency. (Transparency doesn’t work when oping the rendered TIFF directly in InDesign – that was why I never tried TIFF export again.)

PSD is just another format option when you saving rendered images. If you don't have one, you probably not using the latest version of Boxshot. Otherwise, please contact us directly as we will need some details.


May I also ask for an example of those "terrible" results when you rendering in CMYK? Boxshot reads CMYK files and their profiles and should convert them to sRGB properly. If the results are terrible because of sRGB - that's at least expected. If not - I would really like to see an example, as this must be fixed.


As for the timeline, we're going to switch to the linear workflow in the upcoming Boxshot 5, but I can't tell you the release date at the moment, as it is still in progress.

I must admit, that the "terrible" looking results in fact where PNGs (without embedded profile), that where misinterpreted by InDesign et. al. When I manually set the profile to sRGB (and then change it to CMYK) the result is much closer to the original colors. And the TIFF-Workflow described above gives very good results. I used PNG as output format because I just wasn’t aware, that transparency in TIFFs actually works if you open&save them in Photoshop like I described it above. (Maybe this also has to do with RGB vs. CMYK; I should try to import a TIFF with transparency to an RGB project in InDesign.) So please accept my apologies for the harsh words about "terrible" colors.

My Boxshot version was indeed outdated (4.14.2). But even after an update to the current version, I still can’t save as PSD (see attached screenshot).

 

Answered

Got it, thanks. Saving to PSD is currently limited to the Ultimate version only, we'll add it to the Professional version with the next update.


We'll also consider adding output color profile option once switched to the linear workflow.