PDF Optimizer

Transparency

quality The resolution level to use when flattening transparent objects. The higher the level of quality, the better the final output in print or in a browser window. But the resulting PDF document will also be larger.
low-quality Line art and text 288 DPI, gradients 144 DPI
medium-quality Line art and text 300 DPI, gradients 150 DPI
high-quality Line art and text 1200 DPI, gradients 300 DPI