I have an issue with PNG FIles in Indesign and could not find an answer anywhere...maybe I am stupid. I placed various PNG Files with transparent background in INDESIGN = good. When I export as PDF and print it at home = all colours are as I want them to be = good. BUT: When I upload the pdf with my print company the Softproof shows everything converted to RGB (as the PNG File is RGB). Looks like PNG will not get converted to CMYK, instead the whole file will be converted to RGB. Any ideas?
shows everything converted to RGB (as the PNG File is RGB). Looks like PNG will not get converted to CMYK, instead the whole file will be converted to RGB.
Two parts here.
A raster image inside PNG is no more PNG or JPG or whatever... It is a raster image inside a PDF.
The real problem here is that you are not using the correct PDF export setting.
A PDF is an export, let me make that clear, it is NOT the same indesign file you are working.
An export can potentially have several conversions done.
- Fonts to paths
- Transparency flattened
- Resolution resampling and
- Color modes changed... or not.
This is what you need to set, "Convert all color modes to CMYK".
Of course, you need to define color profiles in the first place.
If you want to make super sure, open up your PNG's in Photoshop, save each one as PSD in CMYK, relink the PSD's into the INDD file and export using the Press Quality PDF export preset.
Ok, maybe I have got the solution. I have read a bit more about PDF/X and found that PDX-1a just allows CMYK. Thats what the printing company asked for...but looks like this is the issue as the PNG file is RGB. So I used PDF/X-3:2002 and that worked as it allows RGB too. Funny enough PDF/X-4 does not work...funny
Try exporting the PDF using the PDF/X-4:2010 standard. If possible, use a postscript driver to print. If these two elements are in place, you may not need to convert the PNGs to CMYK at all.