If you have an idea when the object was made, use the information under the relevant date span to narrow down the probabilities. Bear in mind though what you are getting are probabilities not certainties. Many plastics have had long periods of gestation and, as more and more plastics are invented, some become outmoded but nonetheless stay in production. And, although some materials are used most often with a particular manufacturing process, they may also be used from time to time with another. If you have a hunch that an object is made of a particular material outside the dates given or manufactured in a different process go to the material or process in the A-Z guides to check out what is possible in greater detail.
1840-1880
Materials & Manufacturing processes
Bois durci - Compression moulding
Celluloid (see cellulose nitrate) - Compression moulding, fabrication
Gutta percha - Compression moulding, extrusion
Parkesine (see cellulose nitrate) - Compression moulding, fabrication
Shellac - Compression moulding
Vulcanised rubber - Compression moulding
1880-1915
Materials & Manufacturing processes
Cellulose nitrate - Blow moulding, fabrication, thermoforming
Shellac - Compression moulding
Vulcanised rubber - Compression moulding, fabrication, turning
1915-1925
Materials & Manufacturing processes
Casein formaldehyde - Fabrication, extrusion
Cellulose nitrate - Blow moulding, fabrication, thermoforming
Phenol formaldehyde - Compression moulding, casting
Shellac - Compression moulding
Vulcanised rubber - Compression moulding, fabrication, turning
1925-1940
Materials & Manufacturing processes
Casein formaldehyde - Extrusion, fabrication, thermoforming
Cellulose acetate - Compression moulding, fabrication, injection moulding
Cellulose nitrate - Blow moulding, fabrication, thermoforming
Phenol formaldehyde - Compression moulding, casting
Urea formaldehyde - Compression moulding
Shellac - Compression moulding
1940-1950
Materials & Manufacturing processes
Cellulose acetate - Fabrication, injection moulding
Phenol formaldehyde - Compression moulding, casting
Polyamide - Casting, extrusion, injection moulding
Polymethyl methacrylate - Casting, extrusion, fabrication, thermoforming
Polythene - Extrusion, blow moulding, injection moulding
Urea formaldehyde - Compression moulding
1950-1965
Materials & Manufacturing processes
Acrylonitrile butadiene styrene - Injection moulding
Glass-reinforced plastic - Compression moulding, fabrication
Melamine formaldehyde - Compression moulding
Phenol formaldehyde - Compression moulding
Polyamide - Casting, extrusion, injection moulding
Polymethyl methacrylate - Casting, extrusion, fabrication, injection moulding, thermoforming
Polypropylene - Blow moulding, injection moulding, casting
Polystyrene - Extrusion, foaming, injection moulding
Polythene - Extrusion, blow moulding, rotational moulding
Polyurethane - Blow moulding, extrusion, injection moulding, foaming
Polyvinyl chloride - Blow moulding, extrusion, injection moulding, foaming, rotational moulding
Silicones - Injection moulding
1965 onwards
Materials & Manufacturing processes
Acrylonitrile butadiene styrene - Injection moulding
Glass-reinforced plastic - Compression moulding, hand lay-up, fabrication, pultrusion, vacuum laminated
Phenol formaldehyde - Compression moulding
Polyamide - Casting, extrusion, injection moulding
Polycarbonate - Blow and injection moulding, extrusion, foaming
Polythene - Blow moulding, extrusion, injection moulding, rotational moulding
Polypropylene - Blow and injection moulding, casting (film)
Polyethylene terephthalate - Blow moulding, extrusion, injection moulding
Polymethyl methacrylate - Casting, extrusion, fabrication, injection moulding, thermoforming
Polystyrene - Extrusion, foaming, injection moulding
Polyurethane - Blow moulding, extrusion, foaming, injection moulding
Polyvinyl chloride - Blow moulding, extrusion, injection moulding, foaming, rotational moulding
Silicones - Injection moulding