Well i think i may have an idea for this problem.
Make special pppes of different qls that can only make certain qls of armor with them. Make these pppes lvl restricted or skill restricted.
Ex. Ql25pppe soft
description: Used to make soft armors.....
requirements: must be lvl 25 to use this item or have x amount of skills in one or more particular skills
make this go up to ql 150 or 175 and the highest ql one can make all ql of armor as long as reqs to use this particular item are met.
this will keep ppl from make so called tradeskills twinks which is a stupid notion there can be no such thing bcuz u cant really use your tradeskill to there full potential till you are at high lvls anyways.