As a low cost- option in the old days they just used to use any type of foam, (or even expanded cardboard) with some kitchen type aluminium foil wrapped around it.I was referring to the special black foam that the PICAXEs were shipped on.
...
You can wrap foil on a large piece and push lots of chips into it, keeping them oriented the same so it's easy to read all the numbers when you want to find a chip.