How to get proportions right in drawings without a grid - Quora
Keuffel & Esser Paragon 10” Universal Proportional Dividers (55 1126) in velvet-lined case, c. mid-1970s; and K&E Mark 1 8” Corrosion-Free Proportional Dividers (55 1860) in velvet lined case, c. mid-1960s. Made
DAA 899- Making Corrections with a Proportional Divider
How to Scale Up a Drawing
Are You Cheating in Art?, Part 2, by Dilli Rouge
how to make a proportional divider for drawing
Proportional wheel instructions
proportional divider — the basics
4 Easy Ways to Scale Up a Drawing and Save Time