Once I started wanting to keep score of my throws, in order to chart my progress towards competition standard, a single target was no longer ideal because it meant that I would be risking damaging my knives (in fact, by definition, the better I become, there will be an increased likelihood of knives striking one another around the bullseye!).
Consequently I needed to build a three target range but my garden is too small to set up a permanent structure and so it had to be portable, or at least easily put up and taken down again. My solution is not elegant but it has proven itself effective!
Two wheelie bins alongside one another, together with a few well placed bits of wood formed the platform onto which I sat my three rounds / planks. Then I covered the bins with an archery backstop cloth and put a cardboard backstop in place to protect the gates behind the structure. Set up time is less than 5 minutes and the weight of the target faces makes it a stable and absorbent throwing face. Sometimes necessity is the mother of invention!