Next, we prepared the plywood backing. It is 1/8 inch birch plywood, so it is quite flimsy.
First I measured the same distance from one edge at intervals, using some scrap wood to make sure the tape measure didn't go too diagonally, then I used a straightedge to connect the dots.
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|...............| We live in the nick of times.
| Len 17, Wid 3 |
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