Prym (metric) French curve

Also known as a Curved Rule. Used for marking arm/sleeve/neck/hips wherever you need a curved edge measured.

This dressmaker's ruler can be used to transfer the shape of the waist and hips and the in-seam perfectly onto the dressmaking pattern paper or directly onto the fabric. The rounded edges on sleeves, necklines and shoulders can also be transferred flawlessly with the curved ruler. 

The straight grid on a scale of 2.5 x 40 cm allows for perfect transfer of button-holes and seams, while the rounded, narrowing 65 cm scale is ideal for transferring all rounded shapes and curves.