Making slipcastings look more organic

[Mmplin]

Hello! I'm new to ceramics and am looking at ways to make slip casts look more natural, unrefined or textured:

 

Are there any techniques or industry terms around this?

I was thinking of trying to add sand particles to my slip but not sure if that's a bad idea. Thanks so much for any help, very appreciated :~)

[liambesaw]

Grog is what you're looking for I think?

[JohnnyK]

I think that the way you can make things look more organic in slip-casting is to start with your molds and the original pieces you use to cast your molds. Here is a book you might look into to give you some ideas on what you might add to your original positives : https://ceramicartsnetwork.org/shop/additions-to-clay-bodies/  Just "downloading the snippit" will give you enough suggestions to get started...

[Min]

If you add grog or sand to a casting slip you really need to get the deflocculation and viscosity exactly right or the grog (or sand) is going to settle to the bottom of the cast, this is going to take a lot of testing and trial and error to achieve. Other thing is the outer wall of the cast will be smooth from the fine particled clays in the casting slip, grog or sand likely won't  show on the surface like in your first image example. If you do manage to cast with grog dispersed fairly evenly you would then have to scrape down the outer surface to get it to show. Other option would be to use smooth casting slip then brush on a grogged slip on the piece after removing piece from the mould.