Obviously, it needs the designer's awareness of thermoplastic materials performance properties and attributes, and how these properties can be used to solve many design problems so he can make the correct and easy selection of suitable components for manufacture in thermoplastics and the choice of the correct material for each component.  This can involve knowledge of one or more of the following:

• Fabrication technique such as injection moulding, structural foam moulding, Cinpres, co-injection moulding, blow moulding, sheet extrusion and thermoforming - together with any constraints inherent in the method, due to shape, size and cost control.
• Assembly methods such as snap-fitting, solvent cementing, ultrasonic and thermal welding, riveting and screw fastening - and how these can effect component design.
• The dimensional stability of the materials together with any influence on probable service life in normal and severe environments.
• Food contact regulations and flammability standards.  These can help to determine the suitability of designs for selected packaging, construction and other uses.
• Hydrolytic stability and sterilisability (using steam, ethylene oxide or radiation techniques) in order to ensure suitability in many household, industrial and medical applications.
• How to ultraviolet stability affects the design in both exterior and interior applications.
• How finishing techniques can affect the suitability of the materials for a number of uses.

These knowledge and other performance attributes affect not only shape and functional suitability, but often also the economic role of thermoplastics in a given design or component.