The yellow Pee Chee All Season Portfolio was a common American stationery item in the second half of the 20th century, commonly used by students for storing school papers. It was first produced in 1943 by the Western Tablet and Stationery Company of Kalamazoo, Michigan

Kalamazoo, Michigan

The area on which the modern city stands was once home to Native Americans of the Hopewell culture, who migrated into the area sometime before the first millennium. Evidence of their early residency remains in the form of a small mound in downtown's Bronson Park. The Hopewell civilization began to...

. Pee Chees were later produced by the Mead Corporation.

These relatively inexpensive folders were made of card stock

Card stock

Card stock, also called cover stock or pasteboard, is a paper stock that is thicker and more durable than normal writing or printing paper, but thinner and more flexible than other forms of paperboard. Card stock is often used for business cards, postcards, playing cards, catalog covers,...

 and had two internal pockets for the storage of loose leaf

Loose leaf

The term loose leaf is used in the United States, Canada, and some other countries to describe a piece of notebook paper which is not actually fixed in a spiral notebook...

 paper. The pockets were printed with a variety of reference information including factors for converting between Imperial and metric measurement units

Metric system

The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...

, and a multiplication table

Multiplication table

In mathematics, a multiplication table is a mathematical table used to define a multiplication operation for an algebraic system....

. The folders had fallen out of general use by the 2000s,
but are available from Mead as of 2010.

The illustrations on Pee Chee folders changed occasionally over the years, but usually depicted high school age students engaged in sports or other activities. The major difference between Pee Chees and other paper folders were the inside pockets. Pee Chees had pockets located at the sides, not the bottom, which prevented the contents from falling out if the folder was inadvertently stored upside down.