‘Silly putty’ or ‘bouncy putty’ has long been available as amusements. In fact, this type of material – properly known as visco-elastic polymer or dilatent compound – has serious engineering applications and a number of colleagues have asked us to source it for demonstrations or project work in design and technology. This class of material has the remarkable property that it usually behaves as a soft mouldable plastic (like chewing gum), but instantly becomes a rubber if impacted: i.e., it bounces like a ball. One of its uses in engineering is to assist in the machining of turbine blades! It is loaded with grit and injected under high pressure into the small bore cooling channels that are cast into the turbine blades for cooling. The unique rheological properties of the putty are ideally suited for the purpose of polishing the channel walls. Proposed uses in design and technology include: demonstration of an unusual polymer; product sample for toy design and packing projects; unusual products that utilise the inherent properties such as very slow flow or ‘creep’.(The gum version of the putty flows more readily and can be used, for example, as a clock. A ball bearing (or similar) will descend slowly through a tube of clear gum at a uniform rate.) Supplied in 25g container.