Comment on PCBs Straight from the Magazine by DJ

I started making my own circuit boards in the late 70's. Dry Transfer, Ruby Lith, painted lacquer resist, Sharpies, India ink in a plotter, ... I've tried them all at some point. About the only methods I haven't tried (yet) are silk screening and direct milling traces on a CNC machine. A friend once made a hand-drawn board for me using a soft graphite pencil (4B, I think) as an etch resist. It was ugly and had to have a few traces repaired, but it worked. When toner transfer came along, I jumped right in. It took many tries to find a paper that would photocopy clearly, transfer smoothly, AND wash away easily before etching. I found some shiny clay-surfaced paper as scrap at a local print shop and used that for years until I discovered the blue transfer stuff. When I finally mastered the technique I was quite pleased, at least until I started assembling my first board. Many components didn't line up correctly, mostly ICs and radial capacitors. I compared the measurements of my board to the original and discovered the copier I was using at work didn't accurately reproduce the original image. So I grabbed a sheet of grid-ruled paper and copied it onto a transparency sheet so I could easily compare the two. The copy was too narrow one direction and too wide the other. Fortunately the copier had independent X & Y scaling, and after a bit of experimentation I determined I needed to scale the copy 107% one direction and 92% the other direction (I still remember those numbers). This worked well for years until the company bought a different copier and I had to do it all over again. The last toner-transfer boards I made were printed on an HP IIID I rescued from the scrap pile. When that machine gave up the ghost I started ordering boards online, but I still miss making them myself.