Other day I did experiment engraving baltic birch with baking soda trick . Engraving contrast is much much better with this trick . But there comes a problem .This trick leaves black sooth all over the engraved images and when you touch by finger it comes off and spreads on the wood and engraved image .
How do you get rid of black sooth in this trick ?
Regards,
Irfan
Update : I washed the test piece with water .To my surprise picture became dull and lost all the contrast .I think the dark engraving is due to baking soda burning and leaving residue in place .
I haven’t used this trick, but I do engrave on a lot of wood. A tip from Trotec suggests defocussing the lens to increase contrast: Tip: The more you defocus (z-offet: approx. 0.5 - 2 mm), the darker the laser engraving will be. Defocussing the laser beam increases the laser spot size, decreases the performance density and burns more wood instead of letting it pass directly into the gaseous form. The disadvantage of this process is that details can be lost.