The "matte" or "gloss" in a solder mask is set by the mask formulator. In that regard, it is the same as paint. The matte agent is usually an inert filler, like silica. Gloss is a function of light scattering by the surface. Normally, all masks are relatively transparent, so that you can see the outline of the circuitry below the mask. On the other hand, nomenclature inks tend to be opaque, so that they have good contrast to the mask. I don't recall that the IPC has ever tried to quantify "gloss" in any of the revisions of SM-840. If you want to try that, I suggest you fall back on the paint industry standards, but I would guess that your board supplier will not have the equipment to measure gloss. Jeffrey Bush has gone through the major technical considerations in choosing gloss versus matte - ease in cleaning, conformal coat adhesion, nomenclature adhesion, ease of inspection, and solder ball formation. The TechNet archives may be helpful, as this topic was widely discussed 3-5 years ago. I would suggest you list the qualities you want in your mask surface, and work through your supply chain to specify the mask and vendor you want. Denny Fritz MacDermid, Inc. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------