Question: can dpi be too high?
Answer: The higher resolutions for small images are mostly useful for when you expect them to be blown up to much larger sizes for some uses. An A5 at 600 dpi can be blown up to A1 size and still be 150 dpi. 300 dpi is fine. ... If you can't work with vector graphics I would say increase your dpi to 600 just to be safe.