[DaveS]

Kubur: Try phosphoric acid. It is sold at many home improvement stores and is used as a concrete or a metal etch. I have use it for many years on both wootz and layered Damascus. I have tried many different kinds of acids, but for me anyway it seems to work by far the best. I use it right out of the bottle, don't even need to dilute it, unlike ferric chloride where you have to dilute it at least 6 to 1. After polishing the blade and degreasing with acetone, I like to use a paint brush and keep on brushing both sides keeping the blade wet. This should be done outdoors in the sunlight so you can better judge what the pattern is doing. Sometimes a pattern will jump right out. Other times it might take 20 minutes or even longer. Very rarely nothing much happens, in which case you will need to try a different acid. After you get the look you want, rinse the blade in hot water, put a solution of baking soda on the blade to neutralize the acid, dry and oil blade. It seems everyone has their own way to etch their blades, and they all will work. This just seems to work best for me............Dave