From Homestar Runner Wiki
School Paste is the preferred brand of glue in Free Country, USA. It is first seen with Strong Sad in his room. He presumably used it to make a card for Anthony in South Gate, California. It is next used by Strong Mad to make a portrait of Strong Bad, along with elbow macaroni and glitter. The design of the container bears a striking resemblance to the Elmer's line of glue products.