Sandwich was founded in 1998 by Raimund Marasigan and Diego Castillo for the purpose of fulfilling their mutual desire to work together. Castillo recruited former band mates (from The Aga Muhlach Experience) Mike Dizon (of Teeth) to play drums and Myrene Academia to handle bass duties. Marasigan was a judge at a contest where Marc Abaya jammed to a Beastie Boys song with his band, Shirley Beans.

Although existing simultaneously with the Marasigan's foremost band at that time, Eraserheads, Sandwich provided a heavier, grittier sound, and built up their own fan base. Abaya was still in college at the time, and Marasigan would still tour occasionally with the Eraserheads, but these weren’t hindering factors for Sandwich, as there were many sessionists ready to take over in case of a member’s absence.