I am having trouble designing a symbol or block which will white out underneath. I do not want the line work where a boundary intersects to show. I have tried creating polylines then filling the symbol, but when it is exported it shows up black?
Try using a color that is really close to white but that isn’t exactly white ie if white is RGB 255,255,255 use 250,240,240 or something like that so it is near white - white and black are interchangeable colors so use near white for White and near black for black to get what you need.
It has to be off by a certain amount to work - I cannot remember by how far.