Bookbinding and the Conservation of Books
A Dictionary of Descriptive Terminology

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Hertzberg stain

A chemical test frequently used to detect the presence of specific fibers in a paper. The Hertzberg stain not only has a greater degree of color selectivity than any other stain, it also brings out the details of the structure very effectively in the case of those fibers which it does not stain with a selective color. It is prepared from: 1) a saturated solution of zinc chloride in distilled water; 2) a solution containing 0.25 gram of iodine and 5.25 grams of potassium iodide dissolved in 12.5 ml. of distilled water; and 3) the entire solution of number 2 added to 25 ml. of number 1. The colors produced are: 
    Color           indicating the presence of:
    Red             Sulfite or sulfate chemical wood
                    pulp, esparto, straw, bamboo, and
                    most other chemically treated
                    fibers.
    Yellow-brown    Chemical wood pulp which has been
                    incompletely cooked (so as to
                    preserve strength), with the
                    result that some lignins are still
                    present.
    Bright yellow   Materials containing lignin, e.g.,
                    groundwood pulp, jute and
                    unbleached manila hemp.
 (72 , 143)




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