On 2023-01-11 10:42 p.m., Joe Harrington via Contra Callers wrote:
  
 [Thanks] for the idea of using spiral-bound cards rather than drilling my own.  
 Now I might actually do it...
 
 Isaac, try Staples: [...] 
Note that for edge-notched cards, you need a fairly sturdy card stock to 
survive multiple selections. Spiral-bound index cards will probably work, 
but I doubt the paper in a spiral-bound notebook would be up to it.
It occurs to me that you might be able to make custom cards in a 
laser-cutter. (Maybe there's a local maker-space that has one.)
-Michael