Mira wrote: "I've seen this problem with composite layers. It depends on the viewer but is not caused by it. Altium uses two layers to represent filled areas and void." Yes, exactly. I'm plotting *one* layer at a time - not a combined plot - but each gerber is of the composite type. In each gerber are three sub-layers - one with positive copper, one with negative copper (i.e. anitpads and cut-outs), and a third with lines and text. It *only* applies to layers with polygon pours, *not* to plane layers. I define *all* my layers as tracking with polygon pours (including those I'd normally define as plane layers) as the plane layer definition in Protel *only* generates negative CAM planes. I also want to copper pour on outer layers to minimise delamination and EMI. My fab house prefer positive planes because (I'm told) it makes checking with the IPC netlist easier and more effective. And it's easier to visualise, IMHO, if everything you see drawn as copper on screen ends up as.... copper. I've tried viewing the gerbers with ViewMate and CAM350 (as a favour from my last employer) and they both show the same quirk - it is, as Mira says, not caused by the viewer. I don't trust integrated gerber viewers (i.e. Camtastic) as I want to see what the fab house will see - and they won't be using DXP. Of course, Camtastic is matched to Protel so it won't show up any of these quirks. Similarly, I didn't use CAM350 to check board designs in PADS. As it happens, my fab house use Valor, and they *can* accept composite gerbers - but I'd rather not send them composites in the first place. As a short history lesson, PADS gave up on composite gerbers and CAM planes about 7 years ago. It's just too easy to make mistakes. But the company I now work for is smaller and have Protel , so I'm stuck with it! "Contact your fab to make sure they can read your gerbers correctly. Fax them a printed copy of your layers just in case (if you don't want to end up with shorted pins and traces). Mira " Cough!!! Fax!?! :-) Ah, bring back tape and dot, it was all so easy then.... Cheers, Steve P.S. File->Fabrication Outputs->Test Point Report *can* be used to generate an IPC-D-356A netlist from the PCB data. Thanks, Brad! I'll send it to the Fab guys and they can tell me if it's any good.
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