Pick glass

A pick glass also known as a piece glass is a magnifying glass helpful in counting thread count. It is used to determine the number of yarns in warp and weft in woven fabrics and courses and wales in knitted fabrics.
Function.
Pick glass aid in measuring the following.
Ends and picks.
Ends per inch is the number of warp threads per inch of woven fabric. In general, the higher the ends per inch, the finer the fabric is.
Picks per inch is the number of weft threads per inch of woven fabric. A pick is a single weft thread, hence the term. In general, the higher the picks per inch, the finer the fabric is. Balanced plain weaves are fabrics in which the warp and weft are made of threads of the same weight (size) and the same number of ends per inch as picks per inch.
Courses and Wales.
Loops are the building blocks of knitted fabrics, and courses and wales in knitted fabrics are importantly similar to ends and pick in woven fabrics. The knitting structure is formed by intermeshing the loops in consecutive rows.
See also.
Fabric inspection