Sentence:  Many hobbyists are familiar with the material known as "<WSD>eggcrate</WSD>." For those who don't know, eggcrate is made of plastic strips forming a grid of squares about 1/2" wide; it is available in most hardware stores in 2' x 4' sheets and usually costs less than $10. 
Meaning of the word marked with <WSD> tags:  (egg-crating) (plastic mat)