Molds are fungi that can be found both indoors and outdoors. No one knows how many species of fungi exist but estimates range from tens of thousands to perhaps three hundred thousand or more. Molds grow best in warm, damp, and humid conditions, and spread and reproduce by making spores. Mold spores can survive harsh environmental conditions, such as dry conditions, that do not support normal mold growth. Mold growth is encouraged by warm and humid conditions. It is likely to grow and become a problem where there is water damage, high humidity, or dampness. It is estimated that about 50 to l00 common indoor mold types have the potential for creating health problems. Exposure to molds can cause symptoms such as nasal stuffiness, eye irritation, or wheezing. Some people, such as those with serious allergies to molds, may have more severe reactions.
A mold is the basic instrument of paper-making. Consisting of a frame of wood or other material covered with a cloth, polyester, or metal screen and wire, the mold is dipped into a vat containing a pulp and water mixture. It is then raised from the liquid. As water drains through the mold, a layer of fibers collects on the surface which, when dried, becomes paper.