From my own experience from stamping mnemonic recovery words into washers I find it crucial to have a sturdy, solid, heavy and non-flexing base where the washers are placed on. So I wouldn't recommend to avoid using an anvil or some big enough solid block of scrap metal with some suitable flat surface(s). The heavier, the better...
I totally agree.
While stamping, a big part of the process is keeping everything in the right place. I bought a small anvil, and I think it was enough. But of course, a bigger one would have done no harm.
The base, apart from being metal reinforced is made of solid PLA+ or ABS, and it withstands the hammer impact quite well. The washers are grabbed tightly and fixed, which facilitates the process a lot.
The jig I used was basically without any base, and I fixed the washer with simple scotch to the jig base. I have a sense that having a base would cause irreparable damage to the bottom of the jig.
Do you reckon the is not the case and that the whole jig is sturdy enough to sustain such mechanical stress?
In my case, with regards to the base, it has a hole so you can place a metal nut, therefore the washers are placed on top of a steel disc which is on top of a nut, so it withstands the strikes quite well.
I also made a CNC'd base, in anodized aluminum, which is solid, and that will not break for sure. That one is not for sale even though I sent some prototypes, but I am not sure if it is worth it if the regular one with the nut works fine as well.
If you use a jig without a base, and you have an anvil, that should work fine(ofc you will not break the anvil), but in my case I was trying to get rid of the anvil. The solution I made works well on top of a kitchen wooden board, or even these thick kitchen plastic boards for example. Back when I was using the blockmit, I did not have an anvil, and even when I got one, the inner part flew after every strike. The solution with the anvil, I am sure it works fine, but you need many "ancillary" items, and I was focusing on something "simpler" or "cleaner" I guess.