On Feb 6, 2008 5:24 PM, Nodes Norbertwrote: > Hello Mr. Holmström. > > Even after removal with a suitable solvent, a very thin Cytop polymer layer can remain on top of chrome and inhibit etching. > You may have to treat the surface with some plasma or ashing process before chrome etching. Thank you for your answer. This might very well be the reason. The only reason not to believe this is that the surface gold could be etched. But the Cytop might of course stick better to Cr than to Au. I will try plasma treatment. /Sven