Soft (chalk) pastels - How hard would it be to make just a few?

I got a new set of pastels the other day from the thrift store,  but, it's missing my most loved and used colour.



It got me thinking.  Chalk pastels are made from gum Arabic (i have some powder), pigments (i have some yellow ochre)  and possibly other ingredients like calcium carbonate (i have some).

Does it have to be a big batch, or can I make one or two pastels?  

The recipes I can find seem to be for lots.  They do look fairly easy, but time consuming.  

Anyone here got some ideas?

So, after an afternoon of reading books, web, watching videos, etc. I'm very confused about how soft pastels are made.  

Recipes that have gum Arabic as a binder have a ratio of everywhere from 1:20 to 1:80 powdered gum Arabic to water.  Some add glycerin, others do not.

Some only use honey and water. No gum arabic or other normal binder.

Some include clove or other essential oils to reduce mold

Some use only pigment,  some mix pigment with clay, chalk, or limestone powder.  Anything from a ratio of 1:1 pigment to extender,  to 1:6.

Some just mix really well,  others mull the mix for 10 min.


My watercolour mix is 1 part powdered gum Arabic to 2 parts water plus honey and clove.  If I  dilute this 1:20 with water, maybe the binder might work for pastels?