V-Rulers from Tokyo
The V-ruler is such a handy gadget to have among your temari supplies. It allows you to quickly and accurately measure pin placement for guidelines and design threads. These rulers are from the Japan Temari Association. I can send you them at cost.
The V-ruler is marked in the metric system. The smallest marks are millimeters and the largest are centimeters. Note the triangle which marks the 5 centimeter point from the center of the V. When marking temari, you will be dividing sections of the ball into equal lengths, so using the metric system is a must. I find it easy to hook the ruler around a pin and measure in 2 different directions at once.
Vruler, instructions, and 1 laminated C10 magic number reference card $3.50
$3.50