Fluid ejection apparatuses including compressible material

A fluid ejection apparatus comprising:

• a substrate;
• an ejector structure supported by the substrate and comprising:
• a plurality of nozzles;
• a plurality of firing chambers, each of the plurality of firing chambers fluidly couples a common fluid supply channel to a corresponding one of the plurality of nozzles;
• and
• a compressible material between the substrate and the ejector structure forming, at least in part, a wall of the common fluid supply channel to compress in response to an increase in pressure in the common fluid supply channel and expand in response to a decrease in pressure in the common fluid supply channel,
• the substrate including a recess formed to a depth less than a full thickness of the substrate, the compressible material between the recess and the common fluid supply channel, fluid provided to the common fluid supply channel via the recess, and
• the recess having a plurality of posts formed therein between spaced sidewalls of the recess to contact and limit deformation of the compressible material into the recess, the posts having a height corresponding to the depth of the recess.