Obtained at your local graphics arts suppliers or on-line.
A "C-Thru" brand ruler.
The 1/8 inch grid makes marking lines for edge distances easy, and the middle set of numbers makes finding a center easy.
It will handle a Pilot marker pen better than a traditional machinists rule due to the beveled edge.
Comes in many sizes up to 18 inches by 2 inches wide, and best of all, cheap...
http://www.artsuppliesonline.com/cat...m?cata_id=5442
Tip: A useful measuring tool
Linear Mode
