I have a skull from a bear I shot this past fall, and wanted to know; can you spray anything on the skull to help presrve it and look a bit cleaner?  I have heard poly, but don't want it to yellow over time.  I would be thankful for any help on this.  
Thanks and Merry Christmas!!!

Northland I use Krylon acrlic, crystal clear, Satin.It says non-yellowing, but if you spray to much it will look alittle yellow, just spray a lite spray over your skull, and the dust won't stick.  

Got this from and old friend, and have had great luck with it. Best of all, it's cheap.    

Elmers white glue and water to thin it down...smear it on and let it dry. Looks great and never yellows. Have done it on a dozen or more skulls all with the same result and bottle of glue.  

I hope I don't get in trouble for posting a link to another site, but this is a good but long process to make a really great skull mount!

http://www.predatormastersforums.com/ubbthreads/showflat.php?Cat=0&Number=869737&an=0&page=0#869737

I just leave them uncoated.  If they yellow after many years, you could always hit them with peroxide again to lighten them up.