I use either 1/32 which is a tight fit or 1/8 shrink tubing which is loose an$ slightly thicker which I like so it doesn’t melt too much and burn your fingers as much when you pull it off,,, i actually use both though,,,then after you pull it off, flip it and use opposite end to get maximum benefit from 1 piece,,,,eBay sell rolls of like 100 ft for like $10 ech…I go through a lot,,,I also pour my own jigs and paint as well,,,