The simplest way is to get a 4ft x 4ft piece of plywood make a frame with 2 legs one on each side. Then add a 3rd support leg in the middle, to prop ur target up with. For the diana, go to a metal scrape yard and by an old aluminum road sign and cut out a 20” circle. Countersink a hole in the middle of the diana, for the mounting screw. I used a #10 stainless steel countersunk flat head screw to hold mine in place, which hass seen many hits and still going strong. On the back side of the diana I put a rubber grommet washer and a nut, this holds the diana off my target board about a 1/2 inch. Which only allows my diana to ring when it is hit and doesn’t ring on board hits. So it is easy to know if u hit the board or the diana. Hope this helps, these measurements r just a touch bigger than a regulation balearic target board, but r very close.

I use a jury-rigged one with a folded-over duct tape frame and a cardboard diana, and it works well when tied onto a baseball backstop at a local park. I'll attach a photo of it soon.

Looks so simple yet functional, Eino!

Will definitely have to try this, as I am unable to build one out of wood at the moment.

Thanks for the suggestion!

Also a design I'll definitely try out (as I have bicycle tubes lying around)

Thank you Mersa!