12/3 Linen Thread

S351. 12/3 Unbleached Linen Thread from the UK. 100% Flax / Linen. 50-gram spool. Approx. 127 yd.

Due to its strength, linen thread is used to sew signatures in book binding. It is often lightly waxed with Beeswax (S289).

The first number is the thickness of the thread. The higher the number, the thinner the thread. That is 12/3 is thicker than 18/3. The second number is the number of strands that are twisted together to make the thread. 12/3 has three strands. (Flax and linen are two words for the same thing = fabric or thread made from the flax plant.)

All measurements are approximate!
12/3 = 1mm thickness
18/3 = 0.6mm thickness
35/3 = 0.4mm thickness