I have read previously about how you can mix sawdust with glue and create a "filler" for not so perfect joints etc. I am in the process of making a small box which has finger jointed corner. Hand cut, if you want to know, and as such there are small gaps here and there. There are also some joints in the dividers in the inside that need to be filled. The inside is black/ebony, which was achieved through a transtint water based dye. I saved plenty of saw dust and I also have the usual yellow glue as well a hide glue, and of course the dye. I have also read about using Shellac instead of glue.
So how should I go about creating a black paste that I can use to fill the voids.