[Largeformat] TMax and Pinholes

[1990lt5@digizen.net]

I have just started using 4X5 after many years with 35mm and 120. It 
seems that about every 4th or 5th negative I develop has a single 
pinhole (tiny clear spot with no density-never in the same area).  
I'm using Tmax 100 with a Readyload holder developing in Xtol 1:1 
tray processed one sheet at a time.  At first I thought I had a 
problem with my Stop bath (Kodak Indicator mixed 1:43) so switched to 
a water rinse Stop but have gotten single pinholes using both 
approaches.  Boy would I be grateful for some suggestions.  While I'm 
getting some experience with what Tim Rudman "The Photographer's 
Master Printing Course" calls "knifing" it is certainly not something 
I want to become expert at. HELP! Rick Jones