The spore print of a mushroom is an important diagnostic character in most handbooks for identifying mushrooms. A spore print is made by placing the spore-producing surface flat on a sheet of dark and white (or just white) paper . The mushroom is left overnight in this manner. When the mushroom is removed, the color of the spores should be visible on the paper. Incorporating a glass slide allows for examination of spores under a microscope, or moving the spore print to a darker or lighter surface for good contrast.
Mycologists are reluctant to identify any mushroom from its spore print alone since the spore print is only one characteristic used in determination.
Historically the classification of many families of fungi were based on spore colour, an example being Tricholomataceae being a large family containing many fungi whose common factor was having white spores. However recent molecular research has shown some interesting relationships, with some fungi of disparate spore colours showing close relations.