Thank you so much for your replies so far, to answer a few, I need sheets as big as I can, I contacted travis Perkins and the nearest store to me didn't want to know and said it's too expensive for them to stock, SLEC said there1.5mm ply was BBgrade so that's not good enough, robins are sending me a sample, balsa cabin are new to me, has anyone ordered ply from them before, I also got a sample from hanson's which was a/b but again came with a lot of black flecks. I've had some stuff from a model making shop which was perfect, but I paid a lot for a tiny piece which really isn't cost effective.
Thanks !