The specifications for top are determined by the requirements of the end product. The type of garment and/or fabric weight will dictate the specifications for the yarn to be used which will in turn define the specifications of the top. The top maker must use a blend of raw wool that will process to create the required top characteristic (fibre diameter, Hauteur etc). Although there are no standard top orders, there are many similarities between some tops so that combers often make standard house types for general sale.

If a top fails to meet the buyer's specification, a claim for "under performance" can occur. To avoid this, topmakers may use better wool than required. Having knowledge of acceptable ranges in the different raw wool attributes for each component part, the topmaker can define the raw wool needed, taking account of mill efficiency and mill variation.

*Information on this page was sourced from IWTO