hi boysie it is mainly different thickness of soft wood from my timber merchant quite cheap to buy , some planed and some just rough sawn but i am fussy about quality and grain pattern and picking bits that are mostly knot free and without splits , the guys up there are used to me now and dont think it strange when im selecting my pieces and understand what im after , its like you want this bit and i hold it up rub my hands over it whilst looking at grain pattern and spilts and ill say no no good and move onto next bit lol