Muck for slab planting

Hi Everyone,
                    Could someone give me information on"muck",the substance used to retain the compost on a slab forest planting.is it simply brown clay or a substance that can be bought.
Cheers
Colin

I use Keto which you can get from Kazien Bonsai. I mix it with sieved Akadama dust and sphagnum moss. You an use it without the dust but goes further.

Thank you Geoff,that is a great help and I have ordered some from Kaizen
Colin

No problem. glad I could help. It will keep for a long tim as long as it is in a sealed bag.

I ask this some time ago and these are the following responses.

These web sites: http://mypenjing.kdgwild.com/myarticles/muck.html, http://www.whitebearbonsai.com/bonsai%20muck, https://ibonsaiclub.forumotion.com/t7645-recipe-for-muck#79654
(Measure by volume and add water and mix until mixture should be sticky muck that will hold its shape)
* Black Kow (processed manure) chopped sphagnum moss and Bentonite powdered clay
* Eqaul parts of clay, log fiber sphagnum moss and Michigan peat
* 1 part Bentonite, 5 parts Black Kow and 1 part chopped sphagnum moss
* No Clay: dried sphagnum moss, volcanic pumice dust and thickened cornstarch
* 60% Michigan peat, 40% milled sphagnum moss, sometimes akadama or loam, Superthrive