I am reading about toning Vandyke prints and have a few questions. I have read that you can tone them with many of the same toners that you use with Kallitypes, but I have not found any instructions for using platinum or palladium toners. Is the ferric oxalate the reason that the platinum and palladium toners work so well with Kallitypes? Is the lack of the ferric oxylate and the presence of ferric ammonium citrate the difference? Just curious if I can tone the Vandyke's with platinum or palladium toners, and if anyone has any suggestions. Thanks!