Arrowhead Crystals-Auto Tanner

[twinbucks]

  The Arrowhead crystals are advertised as a "blended mineral/syn-tan."  I am assuming the pickling part of these crystals is aluminum sulfate.  Does anyone have any idea what the synthetic part is?  Is the Aluminum sulfate (someone let me know if it's something else) actually replaced by a legitimate synthetic tanning agent, or is this really just another alum crystal tan? 

[Kevin M.]

  From what I have read on here. The aluminum sulfate is an alum tan. Exactly what the synthetic additive is I'm not sure. I use tanning crystals from Van Dykes also a alum tan. With good results.I have been thinking of getting some Syn-Tan to add a little in and see if it made any difference.

[twinbucks]

Is there a way I can test a piece of hide to see if it is truly a synthetic tan?  I believe synthetic tans are washable, so can I wash a piece of scrap tanned hide and see how it holds up?  If so, how should I wash it, and what should I look for?  Are there any other tests I could do on the hide to see if it is an alum tan or synthetic tan?  I've not been dissatisfied with the results, but I just want to know what I'm getting over the long haul for shelf life, humidity resistance, etc.

[frank]

I believe its called naphthalene.Not sure of spelling though.