I found this tip a long time ago, I think on the glass section of Wet Canvas. I’m sorry that I can’t credit the owner of this idea, but it’s neat one.
- Get an empty aluminium (aluminum) soft drink can (soda can)
- Wash and let dry
- Using a sharp knife, scissors, or can-opener, cut off the top and bottom of the can.
- Cut the resulting cylinder into a flat sheet
- Place the aluminium/aluminum sheet under weights (books, bricks, anything heavy) to straighten it. Leave for a some time (hours? days? weeks?)
- From your mostly-flattened-out-sheet cut out a piece approx 12 x 15 cm. Make it as square as possible. (This sort of aluminium is thin enough to be cut with a a rotary paper cutter or guillotine.)
- Using a ruler and a sharp knife measure out sections (a set of two marks) on your aluminium rectangle varying in length between 7mm to 20 mm (or whatever sizes you mostly work with). Leave 5 mm-1/4 inch between each section.
- Using a permanent marker (Sharpie) place a small cross on the sections that will be cut out (ie the lengths varying between 7-20 mm). Don’t mark the space in between the sections.
- Use sharp scissors and/or a sharp knife to cut out the sections marked with a cross.
- Measure your sections, preferably with a set of calipers. Use your permanent marker/sharpie to write down the precise lengths of each section of your measuring stick. It doesn’t matter if a section is not exactly, eg 12 mm, but make sure you know exactly how long it is (eg, 12.2 mm)
You can make several glass measuring sticks from one flattened aluminium/aluminum can.