When Mother remade all her feather pillows in the mid 1950s, the ticking had rows of pink and blue flowers instead of stripes, Dad's overalls were blue striped and Grandpa's khaki pants were made of drill.
I'm pretty sure the print is applied after the fabric is woven and has nothing to do with the type of weave or the thickness. A bright light should help choose a tight weave (driil/twill will be diagonal) and the trusty apprentice micrometer will tell the thickness. A burn test will prove it's cotton. I've always used precut patches just because I'm lazy buy now I'm inspired to take trip to a thrift store micrometer in hand. I imagine those blue chambray work shirts must be about 15, flour-sack curtains about 20, muslin might be as thin as 10 for that hard to start gun.