Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

I had a kind guy in Germany offer to convert photos of three existing mint, populated PCB boards that are the same as three others in an obsolete power supply that have suffered damage over the years from repairs and lifted tracks. the pdf's looked great and were, when printed "actual size" absolutely spot on. But the images from the pdf whether on semi opaque "tracing" type paper or clear acetate sheet are not fully opaque, unlike some commercial ones that i found in my secondhand UV box when I bought it. I used an oldish HP B&W laser printer here at home, then sent the pdf files to a commercial printer who  used some sort of plotter to print to acetate, but still the tracks are only semi opaque, and when I expose photoresist board the pads and some tracks seem to have had patches exposed to some UV so they develop at different times to other regions. this the affects etching....

Could someone kindly look at the pdf's and say if it's an issue with the density of the black in them, as they sort of appear a bit greyish... I have etched boards in the past with photo resist and had no great issues, but these are being a pain! It may be nothing to do with the density of the tracks, it may be my techniques, but I thought i should start at the beginning as I am not sure just what magic he used to go from photos of the tracks on a populated board to pdfs. I can drill the finished boards on a mill with a DRO, all the components are leaded, save 2 small IC's that I will socket. I can use the DRO to perfect, accurate hole spacing for them. But first I need usable boards! The images in pdf form are at http://www.gatesgarth.com/traces.pdf  I am working with Page 4 the traces only, mirrored. I will try attaching, they may be too big.

Thanks you, I am new here and live in the UK, I have much to learn!