Tailor’s clapper is a simple piece of hardwood.
Official one looks like this:
I learned of it from a couple of Craftsy classes (I can write a LOT) about them! This works for jeans. You first blow a lot of steam from iron and then press with this piece of wood until it cools down. This will make the crease so stable and crisp. When I used just steam iron, jean hem couldn’t hold its place. I either hand basted or used a fusible web before topstitching.
The price varies wildly. And based on what I saw on craftsy, I understood that any small piece of hardwood will work (soft wood will warp by moisture from steam). So my husband, who likes wood carving, and I went to Woodcraft store and bought an assorted wood piece – like 1.5″ x 1.5″ x 8″ x 4 pieces. It was about $20. They were all from different woods and I picked the one that was the heaviest. And I use it as is. No grooves, no curves. just a rectangular solid piece of wood. This works!!!! I no longer have to baste the jean hem. It will just stay in place. It is so cheap, if you choose my route. And it improves sewing so much. It is definitely worth getting!