Just curious if anyone might know why certain text or graphic elements in my document will not maintain their transparency values when exported to EPUB?
I've found that if I create the transparency effects in Illustrator and place a link to that in my Indesign document, the transparencies hold through to the EPUB. I also have the EPUB exports settings set to PNG, but it makes no difference.
I had the same issue.
Solution was this for me. My elements that dropped transparency in the ePub where all grouped elements where the transparency was then applied to. The fix was to ungroup and then apply transparency on the separated elements.