Thomas King has an extensive knowledge of all wood used in cabinetry. American hardwoods like Maple and Black Walnut will be used where consistent, stable materials are needed (for example in large interior fit-outs). British hardwoods where a particular emphasis on ecology is required, or for one-off pieces where the quality of material must be extremely high.

The Sheffield workshop has an extensive store of remarkable timbers; particularly favoured off-cuts from other projects, or a piece carefully selected from a visit to a timber yard. These are ready to be employed in particulary special one-off pieces. For some pieces veneers will be used, these allow for the creation of innovative matched patterns and come from timber carefully chosen by expert veneer suppliers.