Words Used Sparingly
Only eighteen panels in, Small introduces his mother and writes: "Mama had her little cough. Once or twice, some quiet sobbing, out of sight […] or the slamming of kitchen cupboard doors. That was her language" (1.18-22). He introduces his family by showing us the passive-aggressive things they do rather than talking—his dad punches a punching bag, his brother bangs on drums, and as for David, he spends most of his time sick in bed. In other words, this is a story about voicelessness.
Because of this, Small relies heavily on visuals to do the talking for him. You know how in horror movies not seeing the monster is often way scarier than seeing it? In Stitches, it's often scarier (or at least more heartbreaking) when characters don't speak than when they do.
For example, the wordless scene in which David's grandmother scalds his hands as punishment is way more upsetting than when she actually glares at him and calls him a "durn little fool" (1.364), because we don't know what to expect. These panels force us to go through the same terror of the unknown, the same uncertainty about what the adults in his life are going to do to him, that six-year-old David feels.