Diagonal Seam Tape is a washi-type tape that is placed on the front plate of your sewing machine to act as a guide while you are sewing diagonal seams.
The red line in the center is aligned with the needle of your machine, and the black lines on either side are exactly 1/4" to each side, to represent a 1/4" seam allowance.
The tape is strong and thin, sticks well to almost any surface, and comes off easily.
Each roll has 10 yards of tape.