Franklin: Sean Clinton's comments are right on the money, let me add a couple of things. In developing, pH and rinsing are the key elements, after your nozzles are clean. Monitor your tests and your developer by pH, (if you are not controlling by pH). Also note, that in many installations the really difficult to clean, and dirtiest chamber is the first rinse, so make sure you are cleaning that out thoroughly, preferably using a good equipment cleaner, no generic chemistry works nearly as well as a good equipment cleaner, and this is even truer in hard water areas. If you were going to do a DOE, I would use pH as a variable that you checked. Rudy Sedlak RD Chemical Company --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------