Dear PKM 25,
Firstly I am always concerned and very sorry when anyone has a problem with one of our products, even if you use an acetic acid based stop bath you should never get pinholes on any ILFORD film product, emulsion being removed from any base requiries some kind of traumatic chemical or temperature based event.
90% of QC enquiries relating to marks of any type on any of our films are related to dust or contaminants preventing development, but you say 'emulsion' is being removed and you have no temperature variation.
As you are probably aware we do not recommend pre-soaking any of our films, in our opinion this is just not required, you do not state if you pre-soaked, BUT regardless, as long as its not an excessive pre-soak that should not affect in any way the performance of the film.
I have checked to see if we have any outstanding QC complaints on DELTA 100 Sheet film and we have none, none outstanding on any DELTA Film product, so as one of the above suggested you should send a sheet of the affected film to us for examination, just send it by post to Technical Service at Mobberley please include your e.mail address, a description of what has happened, your process and the batch number off the box and an unexposed sheet as well from the same box if you have it, you said you can see 'the emulsion' off with a 15 x Lupe, I do not doubt for a second that is what you think you see, but it probably is not, unless its actually reticulation it may well be interference with one of the coated layers, the only way you can actually tell is by using an Electrom Microscope which is what we will use.
You will get back an explanation of what we think it is, that will start with one of three statements :
1 ) Cause justified : A problem has occured with the manufacture of the product.
2 ) Cause not certain : We are unable to determine how or why a problem exists with the sample.
3 ) Cause not justified : A problem was encountered post manufacture.
Simon ILFORD Photo / HARMAN technology Limited :