I am a violinmaker and have purschased Tandy biosilk white leather (chrome free tanning).  I plan to use if for several purposes in my shop, including laying it on my bench as a protection so the violin I am working on is not scratched or dented.  My question relates to concerns of any of the chemicals used to tan / process this leather effecting the varnish on the instrument.  Any insights into how this leather is processed or the chemicals used?  Any ideas would be appreciated 
-Peter