Here is a step-by-step if you are interested in how the felt is made (here’s the whole map-making-madness channel, if you are feeling brave). It covers the creation of a texture in Adobe Illustrator, using that texture image in Pro symbology, then saving and using a saved style. Also, you get to hear my nasally Midwestern accent, which you can take for whatever it’s worth.
At the end I use the created style on some Great Lakes bathymetric stuff.
Adventures In Mapping 