In various embodiments, a tissue thickness compensator can comprise a compressible extracellular matrix and a bioabsorbable material dispersed within the extracellular matrix, wherein the bioapsorption of the bioabsorbable material is configured to leave behind channels in the extracellular matrix. The tissue thickness compensator can also comprise generation means for generating the ingrowth of tissue into the channels. In at least one embodiment, the tissue thickness compensator can comprise dissolvable wicking members which, when dissolved, can leave behind channels in the tissue thickness compensator. In certain embodiments, the tissue thickness compensator can comprise at least one rupturable capsule.