600dpi for resolution when exported. Also, when you export a picture, make sure to do "Export -> in dimensions". That way, it won't pixalate. When it comes to dot screen tones, it varies based off of how clear I want the dots to be vs. how distinct the object it's pasted on is. If the dots are larger (closer to 05L) the dots are more obvious but it can be distracting on top the object. But the closer it is to the other end (to 75L), then the object is more distinct but not the dots.