edy_wheazel - Thanks. How did you remove all the carbon from the etch surface? Did you use the same process that Pettol noted?
Actualy, my method is different. After I prepare the box (sanding and cleaning):
1 - I covered the surface with paper adhesive tape, this kind:
http://renovari-amenajari.com/wp-content/uploads/2012/07/banda_adeziva_hartie3.jpg It's regular usage is to protect surfaces when you paint, it's very cheap.
2 - I either draw the design on the tape by hand, or I print it on a regular paper and put the printed paper on top of the tape.
3 - With a very sharp scalpel I cut and remove the paper from the areas that need etching. The removal is very clean (the paper tape is specialy designed for that and doesn't leave any "dirt")
4 - For etching I make some boundaries with my kid's "silly putty" (plasticine). I do that because I don't want to submerge the entire box in FeCl3.
5 - I pour the secon hand FeCl3 (actualy third, or fourth hand) in those silly putty boundaries. After 15/20 minutes I change the FeCl3 and I let it another 15/20 minutes.
6 - That's it. Take down the silly putty, the paper tape and wash the box. Take pictures and post them on the internet. Have fun.
This methode doesn't involve a printer (if you draw the design by hand) and it's very clean. The only problem is the painstakingly scalpel-cutting operation, but for simple designs it's preferable.
