If the original cap is replaced after each use AND the end is taped off it works over and over again. I actually have let it sit on my printer, after printing, all night and it did not dry out. Typically, a sharpie will cease to work when the cap is left off because the tip dries out and stops ink flow. since the tip is removed, and the filament goes through the internal ink cartridge, the sharpie is a lot less likely to stop working.