Sharpness

I think it would be nice to add the little extra level of reality to some types of painting.

I agree with Nick, since Fresco began as a drawing/painting app I don't think the need for a sharpness filter has ever been a consideration.

I am almost positive that Fresco does not have a sharpen filter feature yet, but you can go to the website below and put it in as a requested feature. https://www.adobe.com/products/wishform.html

Workaround would be to run it through Photoshop add the sharpen filter and then bring it back to Fresco if needed.