Rotring precision templates have perfectly formed, standard symbols chosen for a wide range of applications. They are sturdy and do not warp. Even the smallest lines (like those made with a Rotring fine-lead pencil) are easily visible through the template thanks to the transparent, yellow-tinted material. circles with a diameter of 1 to 36 mm, increased by 1 mm. with a protractor and polygon guides. 6, 10, 16, and 20 mm radii. using a finger lift and a millimeter ruler.