These pencils are a must to write on your vinyl transfer sheets or backing to label them, even the scraps so you know what you have the next time you go to it. Normal pens and pencils will not work on the tack sheets, and some of the backings. They are magic pencils that can write on many surfaces, glass, wood, concrete, vinyl, metal, plastic etc. Professional sign makers use these pencils to mark the proper alignment on their projects. This would be great also for the vinyl placement and then wash away when you are done.