Abstract

Vcininess is the projection on to the leather surface of the paths of blood vessels that are in and just below the skin. Within the leather the vessel lies in a void, and around it the fibre weave changes both in direction and compactness. Hence the leather is thinner at the veininess which therefore misses pressure applied e.g. during glazing, and the veininess is shown up consequently on either surface, grain or flesh. Some work has been done in U.S.A. to reduce veininess by filling voids and looseness in structure by retarinage or by impregnating with resin.

Vessels occurring on the flesh side, or residues of fibres left lying on the flesh side, also make a difference in thickness which will show up as pressure lines on the leather.

As the vessels provide a discontinuity in the texture of leather any method of lessening the difference between vessels and fibres should diminish veininess. Thus, well split up fibres should cushion the vessels against pressure effects; it was observed of a well split up leather that although it showed vessels it showed little veininess. Experimental drying to maintain the splitting up present in the wet leather and to maintain the vessel in pliable, ‘unstuck’ condition has reduced veininess.