At 10:20 AM 2/3/99 -0500, [log in to unmask] wrote: > Quiz: > Name three PCB Tape suppliers.. > OK.. Ones Bishop Graphics. > Get all thre answers correct and become a Certified Hand Taper. Gad, I bought mylar from all kinds of places, and I remember some other company, in fact, two, but the Bishop stuff was quite good and I never bought any of the other stuff. I've forgotten their names. > > Bonus points for answering this question. > Why does the blue grid not show up on the artwork films?? Any printer or graphic artist would *still* know the answer to this. The reason is the same as why graphic artists use blue pencil to mark up films. But my designs didn't have blue grids on them. I never bought that stuff; it was inordinately expensive; instead I used regular mylar I could get at the local art store -- but I ended up buying it in bulk from Echo, I think. Still have some. Nice stuff, for lots of uses. I had several precision grids which I used *under* my tape-ups. The pencil sketch was put *behind* the precision grid so as not to obscure it. The grid was a 50 mil grid (the blue stuff only came in 100 mil grid, as I recall), and I would run the 0.025 tape in the middle of the grid lines, which was much more accurate than trying to put it *on* the lines. This was all at 2:1 scale, so I was getting 12.5 mil traces on 25 mil grid. But I was effectively using a 12.5 mil grid by using the half-grid. My accuracy was consistently better than 5 mils at 2:1, that is 2.5 mils at 1:1. Of course, one of the really cool things about CAD was perfection in the artwork. I pretty much ruined my eyes doing tapeups, or at least fixed their focus at about six inches.... [log in to unmask] Abdulrahman Lomax P.O. Box 690 El Verano, CA 95433 ################################################################ DesignerCouncil E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################