Hi Erik,

I think you and I have different ideas about what a prototype is and is for. I also think it is clear that your company would not have any use for the service I am thinking about offering. Still, there are a couple of points I would like to make just so everyone is clear about them.

...the amateur that build his own MIDI processor may not care that the board slowly oxidizes.

First, not having a soldermask does not mean that the board is unfinished. Boards were given protective finishes long before anyone invented the soldermask, and even longer before the advent of SMOBC (Solder Mask Over Bare Copper).

Moreover, if it is crucial, I can put soldermask on my boards. I also have other finish options at my disposal. On the other hand, these increase my cost, and if I am only trying to confirm that a design works before sending it out for production, I'm not willing to spend money on a 99 year MTBF (Mean Time Between Failures).

I do thank you for your input, and I don't want this to response to sound "snarky," (for lack of a better word). This is precisely the kind of information I hope to get from this thread.