They go around the waist. You make a simple rectangle of fabric with a foldover at the top to slip the flexible plastic through and voila! You have an apron! The plastic hugs your waist.
I guess it's a form of covered boning - steel or plastic Jonathan? making a 'snap on' apron! It's a neat idea. One for your shop maybe Gayle?
What fun. Initially I was thinking they were for the bottom of the apron - creating some kind of ballroom/petticoat effect! Wouldn't be very convenient in the kitchen. It reminds me of that fabric they used to sell that was gathered with elastic smocking at one end. Cut to the appropriate side, sew up the one seam and voila - a skirt... of sorts.
Here is a mid-1950s ad for that fun apron item. The earliest reference to them I found (in a quick look) was from 1950 and the latest was from 1980, in which the writer noted how helpful they were to people who had the use of only one arm.
OH! Lynne, you always find such treasures for us. Jonathan - Do you have a section in the museum - vintage fashion for the handicapped? How interesting.
Yes! I remember using them. Mom had two in the kitchen. We'd thread them through a hem she'd sewn on a couple old towels for my sister and I to do the dirty work. Sometimes we'd mess around and put them around our chests to cover more of our front from harm. Of course I was a lot smaller back then, lol!