EMF is absolutely the wrong format for this, IMO. That something else, is not a viable choice, is irrelevant, unfortunately.
If the charts are fine the way they are in Excel, just copy/paste them into InDesign. If they need tweaking, copy/paste to Illustrator. Tweak there and place the AI file in InDesign.
And stop using 1.3 and start using PDF/X-4.
thank you for your reply bob.
to put a bit more light on the publication process: i won't be able to handle each single chart, because i publish dozens of reports per week (on a daily basis), so charts must be linked to a source (in this case, they are linked to the emf file, stored in a folder where emf files are "constantly" updated). which means that i cannot do tweaking for individual charts--all changes to chart format are made in excel and chart is included "as is" in indesign file
i would love to use pdf/x-4, but that's exactly part of the problem: i can export emf transparency correctly with pdf/x-4, but details in the image look more stark--the effect to the eye (in particular at full-page zoom) being that of a blurry image.
by the way, is there any way to upload files here, so that i can provide an example?
You can post screenshots or link to files in a dropbox folder. That said, you are using an inherently low end, imprecise graphic format and expecting high end results. There are trade offs to be made here.
The best advice I can give you without you actually hiring me to go through your entire workflow, is to stick with solid colors and make sure your transparency blend space in InDesign is set to RGB if these documents are going to be viewed on screen only.
Old one, but...setting transparency blend space to RGB seems to actually solve the problem, at least the problem I had. We can call this post SOLVED I guess...thanks Bob!