Have you ever used masking tape? Also referred to (somewhat misguidedly) as painter's tape? Usually found in beige or blue, and commonly used like duct tape in a 2" wide variety... This stuff is fantastic, but so frustrating. You start to peal it, and no matter how painstakingly slowly and carefully you go, it separates too early from the sides and leaves you with an angled edge on a piece usually much shorter than you'd planned. HOW ON EARTH DO I FIX THIS PROBLEM???... I thought to myself as I attempted to use it to patch a crack missing trim beneath a windowsill in our little home. So of course, after many a failed attempt at discovering the secret to a good clean tear, I did what I should have done in the first place. I turned to the internet for answers.
AND I FOUND THE SECRET. Right here. All you have to do is just what it says. Grip the roll with a few fingers on the inside of the ring and your thumb across the tape below the start of the tear, applying firm pressure. Unroll the tape at a shallow angle, maintaining that pressure (I would stop and move my thumb along with the separating edge of the tape every 2-3 inches). Get the measure of length desired, and tear! Presto! It's easier with a new roll of tape, or a roll with clean, even sides, no dents. If you store it properly, it should stay in like-new shape for a long time and last you quite a few smaller projects. :) Now you know!