I use a compact 2 pound weight on top.

I didn't think about adding weight to my wood clapper. I can sit the cast iron press on top of it. That thing is heavy. Thanks for the tip!

When I'm sewing and pressing away from home I always miss my clapper. I'm a chain piecer and will have one piece on the machine, one piece under the needle and one under the clapper. My seams are nice and flat without fussing with starch. I don't use the clapper for longer seams because I don't have the patience to wait for each bit to flatten. With a wool pressing mat on the bottom and clapper on top, no pressing problems.

My husband is also a woodworker, and he made me a set of 6 clappers, 12" long, enough that I can put them across an entire row seam, or when attaching multiple blocks together. They really make a difference in producing a flat seam. He made them out of maple, a heavy hardwood that gives them the weight they need and put indents in the sides for easy grasping. Since maple is a tight cell wood, he just sanded them smooth, and didn't varnish them, so no worry about the heat from the hot seams transferring any discoloration from varnish.

I use my clappers all the time. I have accumulated a total of 10, but use them all. Especially if I'm chain-piecing.....One for each piece that I've sewn.

DH makes beautiful cutting boards so I got two of those to use as clappers. I can press a 2nd block as the first one cools off. It’s heavy and about 12” square so it does a wonderful job on whole blocks. I also had him cut a slice off my Mom’s rolling pin so it sits flat and doesn’t roll. I use it for a clapper and think of her pies when I use it. Better than stored away in a cupboard.

I did purchased a clapper from Etsy. Very well made, very smooth and heavy.....heavy enough to break a toe on my left foot when I bumped it off the ironing board! Thank heaven it wasn't my machine pedal foot. Be careful what you wish for!

Of all things, there were two June Taylor clappers on the guild's free table at last meeting. I was happy to see two new members taking them. They actually seemed nervous to take items off the free table. They kept saying It's Free?

I've never used clappers but I've thought about ordering one. If you're looking for a way to get your 1/4" seams flat, consider using a seam iron. I have been very pleased with my Clover seam iron. The only disadvantage is that it requires extra caution as the "business" end of the iron is exposed hot metal. Very easy to burn oneself or items in close proximity.

I burned myself with the Clover little iron too much, so it went on the free table at guild. The clapper gets the seams flat enough for me. I don't need the seams to be paper flat to waste that much time on them.

My DH also does woodworking and made a clapper out of a piece of scrap cherrywood. He sanded it nice and smooth. It is thick enough/heavy enough, but not too large to take to classes/retreats.
It never occurred to me to have more than one...