First off, I make my lines as light as possible marking, so there is less cleaning to do after seeing. I Iike using Simple Green and a soft bristle scrub brush, but occasionally I have used mineral spirits on a soft cloth (damp, not dripping if course). As with any chemical used on vinyl or leather, I always test it on a scrap of the material being cleaned to make sure it is not doing more harm than good. Scrubbing with a soft brush in tight circular motion always helps get stuff out of the grain. KEEP IN MIND- always be extra careful when cleaning the area of a visable top stitch, pleat, etc because I've seen even space pen ink get into the thread and any moisture from the cleaner can make this even worse. My general rule is to always test it on a scrap (you may even put a stitch on the test peice) to make sure everything is copasetic. I hope this helps.