There is a problem with the Grid in that when dropping a pre-made image onto it, it snaps to the grid regardless of it's dimensions. This leads to distortion of maps with pre-drawn grids and such, making aligning them a pain. My method: 1. TURN OFF THE GRID 2. Drop your image onto the map layer 3. TURN ON THE GRID 4. If you know the dimensions, set them per-box. When I do maps in Photoshop, my grid size is 75x75, so I just set that in Roll20 and it fits perfectly. 5. If you don't know the dimensions, you need to do some pushing and pulling on the edges (Holding ALT) to get it to fit. The simplest way is to find the center of the map, and line that up with a grid line. Then pull from each end until everything aligns. It's a process you need to get used to, but it goes pretty fast once you've got it down.