What's common between lamps in photography and clamps in workshop?
There's never enough of either.
However, both of these can be unforgiving on the contents of your wallet (or bank account). That's the reason I set out to make a pair of lamps for lighting my pictures using mostly the materials I already had at home.
Since most of the materials I used for making these I already had (disassembled old lamps I used before and did some digging in the garage), the material list is more for the general idea and understanding, rather than a must have. I was making 2 lamps, so if you see double the stuff you think you need for a single lamp in a picture you're most likely right.