Twenty-two mil veneer is a sheet of raw veneer (called a 'face' in the trade) that has been backed with two layers of paper backer before it is flexed and sanded.
The term “veneer matching” refers to matching and manipulating the flitches (small slices of raw veneer) within a single sheet of veneer to create a desired visual effect.
Furniture and fixture makers, as well as musical instrument, automotive, yacht, and recreational vehicle manufacturers use wood veneer because it is significantly more economical than solid wood of the same species.