Sorry about the delay in getting back to you. I just went "online" today! In answer to you questions, may I suggest: 1. You indicated that the mask was "ghosting" onto the phototools and that the mask was depositing onto the phototools from the hole areas. This could be casued by underdrying of the mask (check you data sheet or call your Dexter rep) or by a "hot" running exposure unit or both. Ideally, you want to use a 7KW or 8KW unit that is air conditioned to have short expose times and low heat buildup. Optimum would be a situation where the panel does not exceed 80 deg F during the expose step. You may want to check this out with a thermocouple lead on the panel during exposure to see how hot the panel really gets (I've seen situations where the panel reached 125 deg F - not good!). 2. It seems that your diazo film is being processed correctly. For greater durability, you may want to consider using one of the film protectors instead of the Duratool (Filmgard from MTH or Protek from Teknek). This protective film is really this Mylar (usually .5 or 1.0 mils). This film is cold roll laminated onto the phototools and provides more protection than Duratool. You can use even agressive solvents (such as MEK) to clean off the phototools without worry about attacking the emulsion. These protective films also greatly increase the working life of your phototools. I hope this information is helpful. Please feel free to contact me if I can be af any further service. Larry Fisher Dexter Electronic Materials [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************