There are a lot of different tanning systems available. You will also hear all sorts of strange systems - some will work OK but none will work as well as a good modern system.
Beginners - In my book, I used methylated spirit straight out of the bottle - if it's the purple stuff, you can get in any hardware shop; industrial meths is the same, but has no dye in it. The reason I didn't use a more complex tan solution is that I wanted your attention focused on producing the squirrel. Meths is fine for small mammals especially when you're a beginner.
Intermediate - Paint on tan solutions are a halfway house to a full tan and are easy - just paint onto the skin.
True tanning of a skin can get complex.
Below are some useful links and information on tanning:
Tanning Chemicals Reference Chart
|Tanning Chemical||Type of Tan||Other Materials||Amount Needed to Tan
2 Deer capes or 4 Fox skins
|Color of Hide After Tanning||Leaching of Chemicals
|McKenzie Tan||Brush On Tan||Salt, McKenzie Ultimate Acid,
Baking Soda, McKenzie Relaxer/Degreaser
|8 Ounces||White||No||Hair On Tan||Soft, Stretchy Leather|
|Krowtann 2000||Soak||Sodium Bicarbonate||8 Ounces||White||Yes||In House Tanning||Sets Hair, Pliable Leather|
|Ammonium Alum||Alum Tan||Tanning Oil, Salt, Pickling Crystals||1 1/2 Pounds||White||Yes||Hair On or Hair Off Tanning, (can add brighteners and silver toners to alum).||Sets hair, but skin will shrink. Firm but pliable leather.|
|Potassium Alum||Alum Tan||Tanning Oil, Salt||Paste Tan
Can be re-used
|White||Yes||Hair On or Hair Off Tan||Sets hair, but skin will shrink. Firm but pliable leather|
|Aluminum Sulfate||Alum Tan||Tanning Oil, Salt, Pickling Crystals||2 Pounds||White||Yes||Hair On or Hair Off Tan||Sets hair, but will shrink. Firm but pliable leather|
|Vegetable Tan||Tanning Oil, Salt, Pickling Crystals||2 Pounds||Pale Brown||Very Slow||Hair Off Tanning, Cow hides, Dyeing Tanned Hides||Dense, Firm or Solid Leather|
|Curatan®||Oil and Mineral Tan||Salt, Pickling Crystals||8 to 10 Ounces||Light Buckskin||Slow||Hair On or Hair Off Tan||Soft, Stretchy Leather|
|Tannium®||Chrome Tan||Tanning Oil, Salt||1 Pound||Pale Blue or Green||No||Hair On or Hair Off Tan, Garment Tan||Soft Leather|
|LUTAN FN||Alum Tan||Tanning Oil, Salt, Pickling Crystals||1 Pound||White||Very Slowly||Hair On or Hair Off Tan, Garment Tan||Soft, Stretchy Leather|
|Liqua Tan||Syn Tan, Synthetic Tan||Salt, Pickling Crystals||2 Cups||Cream||No||Hair On or Hair Off Tan||Sets Hair, Firm Leather|
Tanning with HQ Tan 5000
See links below for more advanced tanning info:
McKenzie tanning videos below:
Paring the skin
Tanning the Skin
Hope this helps.