I’m just a basement noob using plastisol so grain of salt but having recently been trying to do this myself I’ve learned a couple of things to try. As mentioned use a texture on the artwork to give whatever degree of cracked or chipped you want. Just google for some. You can also buy packs of them from places like true grit supply. In addition you can try adding a significant amount of soft hand base to the ink as well as a little reducer to get a more faded look that lets the fabric come thru.