The pattern as you see it, once cut, will hold together 9 ceramic tiles of 2mm thickness each. The tiles will be glued on to the plastic template/holder. The finished item must be strong enough to maintain its own shape and not snap or bend or whatever. It should also be flexible enough to place over a football and held down with adhesive gel and some tape. Once the securing tape is removed, the item should return to its original (flat) shape. There will be no lateral forces like pulling in different directions or anything like that. The only forces envisaged will be when you try to peel it away from the "football", as the adhesive gel will resist somewhat, so removing will be done carefully.
For the plastic holder I have tested 1mm plastics, they are way too thick to flex at all.
I have in front of me polysterene 0.5mm and it looks poerfect in terms of strength and flexibility. But there will undoubtedly be other plastics I could use. I am expecting more materials to arrive tomorrow.
How is it done currently: The 9 ceramic tiles are secured together with silk tape (used for bandaging). The adhesive on the silk tape holds the tiles in place. The whole assembly is then secured over the "football" with hypafix tape, this is semi flexible adhesive bandage. Once used, the pad is removed, the hypafix tape peeled off and thrown away, and the rest (tiles + silk tape) are immersed in water in order to wash away the adhesive gel. This continuous immersion in water takes its toll and the silk tape's adhesive can only do so much before it leaks and when the water dries it becomes brittle. In addition because the silk tape frays, I have to stitch it on the sides making something like a hem.
So although I already have a working solution, I am looking to improve it.
The idea is to glue the ceramic tiles onto the plastic holder with some sort of glue, epoxy, two part, whatever is appropriate, and this glue will not be affected by water and continuous washing.