Etching brass?

[boppa]

for PC boards, the process is to laser print a negative of the design on glossy photo paper, lay the design down on the copper clad board, and iron the pattern onto the copper clad board. The heat from the iron will transfer the toner from the printed image to the copper board, and when submerged in the etchant solution, all will be etched except where the toner is. When I have done PC boards using this method, it reproduces details and fine lines quite well. I wonder if I could, for instance, take the a drawing of a tender with the rivet detail, iron the image onto brass, and etch it to leave the rivet detail raised above the rest of the brass.

this is something I have had a lot of experience with (copper etching- not brass)

HEAT TRANSFER (photo) etching as described above is the most accurate way of etching (to within 0.1mm accuracy easily or better with copper, brass should be just as acurate)
I have handmade PCB's with 0.25 mm wide tracks with 0.1mm spacing from a laser printer and `iron on' ie heat transfer prints with a better than 50% success rating

photoetch is WAY more easy and more importantly accurate than heat transfer etching, and more importantly it has less `blurring' if you can time it

hardest part is that both methods require etching times- and they depend on acid strength, time, heat and the angle you hold your head at....

(seriously- its almost `black magic' etching stuff- a good etcher can do `magic' a bad one can't..- you have to `know' just when to pull it from the acid for accurate results)

EDIT TO CHANGE PHOTO TO HEAT TRANSFER

(2 different ways and heat transfer is less accurate than photoresist methods)

undercuts etc sound like poorly applied (ie unclean surfaces) and overlong etching times...