Mike Harrison wrote: > Forget fancy films - use tracing paper - at least 90GSM weight so it doesn't crinkle. The Fotoboard2 datasheet disagrees with you, and (partly) agrees with me... "However it is very common to produce artwork using PCB transfers applied to drafting film (TRACING PAPER IS NOT SUITABLE)" [ emphasis mine ] "The use of photocopies on acetate film should be avoided as the image is usually not black enough to prevent the UV light from exposing the resist. If there is no alternative then the image should be traced over using drafting ink until the image is totally opaque." Given that laser printers use similar technology to photocopiers (the expose-transfer-fuse cycle is essentially identical aside from the printer using a laser to expose the OPC drum), it isn't that much of a stretch to assume that (at the very least) some laser printers would be unsuitable... Interestingly the Seno developer used for Fotoboard has the a similar mixed strength to the CPD5 developer used for Microtrak. CPD5 is 11% unmixed and mixed 1+4 to give a 20% * 11% = 0.022% mix. Seno 600-010 is 33% unmixed, 1+9 strength, to give 10% * 33% = 0.033% mix. Both are metasilicate based. So I have no idea why the CPD5 near enough stripped the photoresist. Although the Seno datasheet actually specifies that for Microtrak the 600-010 should be used at a 1+15 ratio, or 6.25% * 33% = 0.21% mix... So theoretically the Fotoboard shouldn't be getting stripped by the CPD5, but actually it is. Very weird, unless there's something else in the CPD5 developer that isn't listed in the MSDS... -- Phil. piclist@philpem.me.uk http://www.philpem.me.uk/ -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist