Reply To: PDF/X and Color management in InDesign

As you pointed out, the pdf/x-1 “looks” right, and it is right, but if you would try to select objects in the pdf, you’ll notice that if you move a “transparency” figure, it is composed of lots of little objects. If you do them same with a pdf/x-4 the “transparency object” will still be one object.
Also, the settings are different. Look in the “advanced” tab of the pdf-presets and you’ll find an option “transparency flattener”, which is grayed out in pdf/x-4 and not in the pdf/x-1.
For the best flattener presets for CMYK check: https://www.digital-engineer.net/archive/entry/indesigns-hidden-transparancy-flatteners/
and look for “gwg2400”.
So, it’s not the pdf which can cause trouble, but the way it’s made. Old rips don’t support pdf/x-4, so a pdf/x-1 is needed, and flattening will be needed. If it’s a complex design, it can mean trouble, but not always.
Hope this helps a bit more.