Ware do I find seat foam by itself. If I am able to find a carbon base, how do I find seat foam without robbing it from another saddle? The covers are easy to find.
I’m so glad you asked this question. I’ve been wondering myself for quite a while now.
I’ve searched for neoprene foam, but have no idea what density or thickness to buy for a seat. I hate getting stuck with a bunch of material I’ll never use.
Thought about yoga mat, seems close, but probably too soft.
Try an upholsterers. They may have some waste they can give you for free.
i use sleeping pads.
they are light, cheep, easy to cut, you can do a many layers you like, or do smaller layers in the middle to flat the form
and most important for me, cause i am riding a lot in wet conditions and near the water…it dont take any water, the saddle is always dry & your ass will be dry 
Seat foam
Jogi, can you post a picture of what you are talking about? I like the idea of the seat not absorbing water!