Types of sheet materials
SHEET MATERIALS/ BOARDS.
There are many different types of sheet materials on the market that are used in constructing scenery the most common being plywood, chipboard, medium density fibreboard (M,D,F) and oriented strand board (O.S.B). Sheet materials can be supplied in various different sizes and thicknesses, the most common board size being 2440mm x 1220mm and the most commonly used thicknesses being, 4mm, 6mm, 9mm, 12mm, 15mm, 18mm, 25mm.
Plywood is constructed by taking sheets of thin wood or veneers as they are called and glueing (laminating) them one on top of each other with the grain running at 90o to the previous sheet. There is always an uneven no of sheets i.e. 3, 5, 7, etc this is done to keep the board stable and to prevent it from warping.
Chipboard as the name suggests is made up of wood chips and sawdust bonded together with glue and compressed.
M.D.F is made up of fine fibres bonded together with glue and then compressed.
O.S.B is made up with large flakes and wood chips, glued and pressed together.
All these products have their own strengths and specifications (specs), which can be obtained from the supplier or manufacturer. These specs are an important factor to be considered when building structural components, as they indicate the weights and loading which can safely be applied to the materials.
There are two other types of plywood use in scenery construction, skin ply and bendy ply. These materials are used in the construction of curved scenery.
Skin ply as it is commonly known is a very thin three-layer plywood 1.5mm thick. As it is very thin and pliable, it is ideal for bending round curved shapes.
Bendy ply or flexy ply, is a fairly recent product and has been designed specifically for making curved and convoluted shapes and structures. It is extremely pliable in one specific direction dependant on which board you are using ( short grain or long grain)and will bend round tight curves.
There are many types of sheeting and board materials on the market which are not included above, however the products mentioned are probably the materials you will encounter most in scenic construction.
Dust masks should always be worn when cutting composite board such as M.D.F.