All we use now is sp101 or FG1 plywood. Anyone not use them ? had a try of that Q mark ply and thought it was crap.
Always use Sp or Fg and have done for a while now. I did just have to ply out a chequer plate staircase, and used 9mm Sp101 on the risers. Could n`t get 11mm so used Marine from a local supplier. It was good stuff but expensive