Because I use the photofabrication method, I was just wondering if I could do one side completely, drill alignment holes and then do the other, but this time, I'm thinking of leaving the photoresist on the completed side, so the etchant won't work well.

But then what time constraints are there to ensure the photoresist stays on my design on both sides, when both sides are developed and one side is not etched?

I'm asking about photoresist, because it protects the copper underneath from being eaten.

I have a special (long halogen) black light that develops my boards nicely.

as for the white coating that I peel off, I am not comfortable with putting that back on because it might not work.

If there is anything else I can apply to the completed side that can prevent etchant from eating the copper, let me know.

thanks.