Accurate ruler sew on patch

It's accurate! you never know when you need to measure something, so might as well have a ruler attached to your clothing. 
All patches are silk screened, hand made by me. They are safe to go in the washer, but may fray a bit, depending on how you sew it. Do not iron directly on the ink, it's best to iron from the backside, with a piece of fabric or paper between the iron and the patch.  Black and natural fabric is a heavy weight cotton canvas. Any other fabrics are either upcycled from old clothing, or thrifted and will vary in weight and may show slight sings of wear.