this may be a double post , having computer trouble.
Learned this trick fro Daryl Hibben a couple of weeks ago. It works equally as well on Ivory, Stag and bone.
Get some potassium permanganate from a drug store or chem supply store. Should only cost 5-10 dollars for a 100g bottle.
Follow precautions on lable this stuff can be dangerous!
Place a few crystals in a saucer and dribble some water on it. Don't panic when it turns PURPLE. use a small brush to apply solution to stag/ivoty/or bone. The more you apply the darker the matterial will turn brown when it gets dry. Apply in stages to get desired shade.
Test on a scrap of material to alay any fears before you use on expensive Ivory. You will be pleasantly surprised.
Good luck.
Jim Ziegler aka Kraut