I have tried that, it doesn't seem to get rid of it.
I'm using a Laser Printer if that makes a difference??
It will print correctly from InDesign, but not if I export it to PDF....
What export settings are you using to make the PDF?
Does it help if you use PDF/X-4 or another setting that does not flatten the transparency? How about if you use a tranparent .psd instead of .png?
PDF x4 didn't work - though I'm not sure if I had the right settings to make it compatible?? I've also tried PDF 1x.. (didn't work either)
I have just been export as a High Quality print, I've tried low, med and high res transparency flattener, I've tried changing colour profiles of the document, and of the images, (matching and different between the two) I've tried transparent PDFs, PNGs, and PSDs..
I've managed to get it to work if I print from RGB colour profile, from InDesign, but I need to convert it to CMYK to get it printed externally, So I'm concerned that whatever I get to work on this printer has to also work on their printers..
Is their a correct way to use transparency, and export it? That I (must not be doing but) could learn the correct way to do it?
So this is just an in-house proof?
If you read the InDesign Secrets article you know that the problem is in how the printer is flattening the transparency -- treating raster and vector areas differently, and what your laser printer does is not necessarily what the imagesetter at the printer is going to do. Adobe recommends PDF/X-4 for delivery to any printer that can handle it. It preserves both transparency and color and moves the color conversion to the RIP for best results. Can your commercial printer work with a PDF/X-4 file? Have you asked them for their recommended PDF export settings? You should deliver what they ask for and get a contract proof.
If you are in some backwater where the printers are still using 20th century technology and they insist on flattened PDF, like X-1a, then I recommend you get the correct color profile from them and consider converting the RGB .png images (which are not intended for print) to CMYK .psd and make sure the backgrounds are also in CMYK, then make the custom flattener, as described in the article.