Definition:
A popular type of needlepoint canvas that has a single horizontal thread, and two finer vertical threads that wrap and twist around the horizontal thread to create a locked mesh at the intersections (hence the name “interlock”). Projects worked on interlock canvas tend to have less distortion after stitching due to the locking of the mesh. Also, stitches stay where you put them, unlike mono canvas where the stitches can move due to the intersections not being connected or "interlocked."
TIP: Holes in canvas can be easily repaired. See the Repairing Needlepoint Canvas article for more information.