So, Just What Is "Kentmere" Darkroom Paper Supposed To Be ?

[miha]

... By the way, even Agfa used a secondary-brand.

Perutz?

 

[AgX]

Yes. And I assume it were same films.

 

[MattKing]

Even Kodak did it.
Bob Shanebrook (laser) has mentioned he was responsible for the production of both Plus-X and Verichrome Pan during the last years of Verichrome Pan. And he has told us that the emulsions were identical - what differed (mainly) was the anti-halation and some other production cost minimizing factors.
Verichrome Pan was, of course, only available in roll film sizes - not 35mm.

 

[gorbas]

I was under impression that Verichrome was 2 layer emulsion, slow and fast and that contributed to its exposure latitude necessary for all those limited exposure settings on amateur Kodak cameras of the time?

 

[Sirius Glass]

I was under impression that Verichrome was 2 layer emulsion, slow and fast and that contributed to its exposure latitude necessary for all those limited exposure settings on amateur Kodak cameras of the time?

That is what I thought and the problem was that it had Cadmium in it which is toxic and that lead to it being discontinued.

 

[MattKing]

I was under impression that Verichrome was 2 layer emulsion, slow and fast and that contributed to its exposure latitude necessary for all those limited exposure settings on amateur Kodak cameras of the time?

Not for the last several years of production.
I'm assuming that the reduced anti-halation fulfilled some of the latitude related requirements.
Here is one of Bob's posts on the subject: https://www.photrio.com/forum/threads/develop-the-negative-of-type-55.174246/#post-2267166

 

[Lachlan Young]

I was under impression that Verichrome was 2 layer emulsion, slow and fast and that contributed to its exposure latitude necessary for all those limited exposure settings on amateur Kodak cameras of the time?

Verichrome maybe, not necessarily Verichrome Pan. And you can make two (or more emulsions) of different speeds and blend those, and coat as a single layer - or make 3-4 and coat as two layers of various blends etc. If you don't need to coat as discreet layers and can blend/ coat two emulsions as one, you do so (fewer interlayer interactions to negate). It might have been a bit pioneering in the 1930s when multiple layer coatings were a bit of a challenge, but not by the 1950s, let alone today.

 

[Lachlan Young]

I've heard that the loss of Kentmere fibre based papers were a massive event for Bromoil practitioners likened to the loss of a loved one...

Probably only the ones that were made in non-supercoated form.

There is virtually no difference in speed between MG5 and Kentmere now after the MG5 was introduced I checked each and for a 12x16 print one on Kentmere took 44 seconds and the same print on Ilford took 41 seconds. My eyes, whilst they are getting old still have very good colour vision and the MG5 is, in comparison to Kent mere RC, very much on the warm side of the spectrum. Kentmere is a neutral to cold tone. The neg I used was exposed without any filtration in either case, in other words grade 2

The old MG4 had several inherent faults with the tonal gradation with filtration having a big step between Gd2.5 and Gd3. These steps have now been ironed out with MG5. (Not my words but those of an Ilford tech who gave a talk at my Photo club a year or so ago. Additional changes are the depth of black with MG5 is much deeper than MG4 (Ifords words at the same talk), and again comparing my prints from the same negative bear this out (my test, not words from Ilford)

It's almost like Ilford know what they're doing... [pardon my sarcasm]

It's also reassuring to get official confirmation of what was observable with MGIV in terms of grade steps. I do wonder if Ilford are planning to rejig the Cooltone RC and the WT RC/ FB emulsions - and if the MG5 emulsions will go to FB or not.

They are indeed different film. Just looking at the technical data sheet one can see the developing times to be way apart.

A reasonable conjecture might be that Pan 100/400 are made on the older emulsion mixing plant used for Pan-F+/ FP4+/ HP5+ - and that the Kentmere ones are made on the 'rapid-mixing' plant used for Delta (and XP2, I suspect) and the paper emulsions since MGWT. If you are making a 'generic' set of emulsions that don't need as much pushability (or more moderate developing times to reach higher densities), reciprocity correction, specific colour sensitivity, the finest possibly granularity for a particular halide structure, extra high sharpness, sophisticated anti-halation solutions or extremely tight batch-to-batch consistency etc - then you can omit a lot of expensive research and components. With the rapid-mixing plant, my understanding is that it's relatively easy for Ilford to produce fairly bespoke products at will.

 

[miha]

A reasonable conjecture might be that Pan 100/400 are made on the older emulsion mixing plant used for Pan-F+/ FP4+/ HP5+ - and that the Kentmere ones are made on the 'rapid-mixing' plant used for Delta (and XP2, I suspect) and the paper emulsions since MGWT. If you are making a 'generic' set of emulsions that don't need as much pushability (or more moderate developing times to reach higher densities), reciprocity correction, specific colour sensitivity, the finest possibly granularity for a particular halide structure, extra high sharpness, sophisticated anti-halation solutions or extremely tight batch-to-batch consistency etc - then you can omit a lot of expensive research and components. With the rapid-mixing plant, my understanding is that it's relatively easy for Ilford to produce fairly bespoke products at will.

This is quite an insight, and if correct, it makes perfect sense to me.

 

[BMbikerider]

Probably only the ones that were made in non-supercoated form.



It's almost like Ilford know what they're doing... [pardon my sarcasm]

It's also reassuring to get official confirmation of what was observable with MGIV in terms of grade steps. I do wonder if Ilford are planning to rejig the Cooltone RC and the WT RC/ FB emulsions - and if the MG5 emulsions will go to FB or not.



A reasonable conjecture might be that Pan 100/400 are made on the older emulsion mixing plant used for Pan-F+/ FP4+/ HP5+ - and that the Kentmere ones are made on the 'rapid-mixing' plant used for Delta (and XP2, I suspect) and the paper emulsions since MGWT. If you are making a 'generic' set of emulsions that don't need as much pushability (or more moderate developing times to reach higher densities), reciprocity correction, specific colour sensitivity, the finest possibly granularity for a particular halide structure, extra high sharpness, sophisticated anti-halation solutions or extremely tight batch-to-batch consistency etc - then you can omit a lot of expensive research and components. With the rapid-mixing plant, my understanding is that it's relatively easy for Ilford to produce fairly bespoke products at will.

I think Ilford actually do know what they are doing or they would not be in the position they are.

However, if I can if you agree with my analogy put some meat on the bones about Kentmere and. Ilford.as it was explained to me. Kentmere was a small independent company based in a small village in Cumbria in the north west of England called Staveley. (See the picture below) The area is mostly farming so as an industrial site was to me, a bit out of place. The factory occupied an area around 150 meters square, give or take, so it was quite small. It did it's own thing and the products were respected and widely used. It was hinted that their working practises were outdated and the company was not doing well. They had their own film production line for film and made several unique types of paper unobtainable anywhere else. These gradually disappeared leaving only the lovely fibre based multigrade heavyweight paper, which was at the time considerably cheaper than the same type made by Ilford and also the RC multigrade which is still sold under the name of Kentmere, but made by Ilford.

Then in steps, Ilford took over. Anecdotal information is that when they went to look at the Kentmere factory which I said before was small - actually it was minuscule, compare the Ilford's main factory in Mobberley, Cheshire in the West midlands area of England. What they found were working practises that were well out of date and some chemical procedures using ingredients which alarmed them due to Health and Safety issues. After the purchase of the Ilford company the lovely Kentmere multigrade fibre based papers disappeared but the resin coated version remained. Cynically, at the time I thought it was due to Ilford not wanting a better product to be sold under the name of a rival company. (at a cheaper price) I don't know if there were any changes made to the composition of. Kentmere branded films remained in 100 and 400 versions. As far as I know these films have not changed in their formulation.

The Ilford Pan 100 and 400 have been around for a while, when they first appeared I think was before the takeover of Kentmere so they may not be the same emulsion. A sure fire way to check is to look at a cassette of film, under the light trap is a barcode with numbers above. For Kentmere 100 this number is 017701.. I don't have any Pan 100 to compare, but for FP4+ is 017564 so you get the idea. If a film is made by one company, but sold under a different name, this number will be the same......3 or 4 years ago it was rumoured that colour negative film sold under the Agfa Vista lable, was in fact made by Fuji. I had both films in storage at the time so when I checked this, I found in fact they were the same number. This was also confirmed in a UK photography magazine. As I said, I used both and films and when printing colour there was virtually no change in colour filtration needed.

The Ilford stopped making MG4 to be replaced with MG5. It has been said over here that MG5 will not be made in Fibre based paper but it has been in the UK magazines that the emulsion has been 'tweaked' to bring it up to date alongside MG5 but the name is not going to be changed. The Factory used by Kentmere is still there with the name clearly visible on the wall. It is in use but if it is still occupied for making photographic items I have no idea. I assume it is because their logo is a trademark

For those interested Ilford Pan 100 and 400 is available in UK from a company called Firstcall (www.firstcall_Photographic.co.uk) and I think they will export it.

The Image of the Kentmere factory
This is an image taken from a Google street view of the Kentmere factory with the name and logo. This has changed since I last saw it about 3 years ago when the name was on a board fastened to the apex of the roof. It was the old logo so it could well be still used for limited manufacture or administration. The small notice on the side directs visitors to the reception.

 

[pentaxuser]

I think Ilford actually do know what they are doing or they would not be in the position they are..

A very good potted history of the Kentmere factory and I agree Ilford does appear to know what it is doing

I have seen your comparison pics of MGIV and what Ilford now calls its new paper which gets referred to as MGV but is actually called DeLuxe and I thought the improvements looked very clear to me, especially that of deeper blacks

pentaxuser

 

[markbau]

Even Kodak did it.
Bob Shanebrook (laser) has mentioned he was responsible for the production of both Plus-X and Verichrome Pan during the last years of Verichrome Pan. And he has told us that the emulsions were identical - what differed (mainly) was the anti-halation and some other production cost minimizing factors.
Verichrome Pan was, of course, only available in roll film sizes - not 35mm.

I've heard this before but I seriously doubt it. The two films printed completely differently. When I first started trying PMK I used both films, the stain on VP was strong, the stain on PXP was weak. Personally I think that VP was Kodak's finest B&W film. I messed around with PXP a bit but never liked it so I find it really hard to believe that they we the same emulsions. They were chalk and cheese.

 

[markbau]

That is what I thought and the problem was that it had Cadmium in it which is toxic and that lead to it being discontinued.

That's exactly what the Kodak rep who used to visit Lindahl's in Denver regularly told me. Cadmium was the problem and the reason Kodak dropped it. If VP and PXP were essentially the same emulsion, PXP presumably has Cadmium, how come PXP continued for quite a while longer?
The same Kodak rep (I became good friends with him) told me that Kodak was doing everything possible to move people away from all their existing B&W films to get them to buy TMax as it was so much cheaper to produce.They spent megabucks advertising and pushing TMax, also employing some big names to push it, John Sexton comes to mind.
It was all to Ilford's advantage as many people stopped buying Kodak B&W film and migrated to Ilford, although TMax did develop a following.

 

[Pat Erson]

Lachlan Young in 2017 when Phorio was APUG :

"as I understand it from hearing an interview with one of the senior emulsion chemists at Ilford (cannot remember where it is posted, but it's from a podcast from one of the factory tours), they [Ilford] took over with the intention of learning the recipes & techniques over a number of months prior to transferring production to Mobberley, but when their senior engineers went in, they had kittens over the non existence of basic workplace health & safety - lack of machine guards on coating equipment used in low light levels & open reactor vessels were two that were cited specifically.

They had to shut the plant down very quickly, then try & re-make the emulsions at Mobberley without the 6 months learning they'd planned on. I recall that the POP went because it presented 'unacceptable risks' to those manufacturing & coating it, Kentona went because it probably needed a massively costly re-engineering job relative to its sales potential. ART300 is clearly a descendent of the ideas of similar Kentmere papers, but on a far nicer base"

Ian Grant from the same thread :
"Lachlan is right on the other details, the health and safety aspects were a major issue to particularly the POP paper which contaminates everything with Silver Nitrate. Kentmere coated it before their Christmas shutdown each year then had to decontaminate everything before the line could be used again".

 

[AgX]

The Image of the Kentmere factory

I read between te lines of postings referring to Kentmere quite some misunderstanding.

Harman did not buy Kentmere as such, but only their photographic business (without going into detail what assets this buy included), but leaving the resting production with Kentmere. That is why there still is a Kentmere factory, active on another field.

Also the photographic business of Kentmere when this was still active its last years was very small.

 

[Don_ih]

As an aside, Ilford is calling their new Multigrade formulation the "fifth generation" and also called MGIV "deluxe" (as opposed to Kentmere, which they call "select"). They're just not labelling it "MGV" - maybe because that's not enough letters for them.

 

[Lachlan Young]

@BMbikerider I should have been clearer, my sarcasm was aimed at those who spend enormous amounts of time and energy accusing Ilford of all sorts of conspiracies that make little sense.

Regarding Kentmere, I think they effectively made only a handful of paper emulsions - Bromide (in 3 grades) - which was probably also Kenthene, Kentona (single grade), and the VC one (one emulsion contrast - but 2-3 different speed emulsions, blended & with ballasted dyes) - and the POP one (which I think came about as the result of a long tail of a nuclear defence product made for the MOD on an RC base). All the 'special' products seem to have largely consisted of a Bromide or Kentona emulsion on different substrates. I suspect that it may have been (too small) market demand rather than outright technical difficulties that stopped Ilford working out how to make Kentona on M14.

Cadmium was the problem and the reason Kodak dropped it. If VP and PXP were essentially the same emulsion, PXP presumably has Cadmium, how come PXP continued for quite a while longer

I don't think this was the case. Cd seems to have been largely removed from Kodak products in the 1970s. There seems to have been a lot of nonsense (not always shut down by marketing departments - it probably helped to mislead their competitors as to what they were doing for a few months) about cadmium, when there were many, many other emulsion/ emulsion making changes also taking place over the same era - all of which may have far more dramatic impacts in less-than-obvious ways than people want to believe - and the reality of the importance of market share in terms of enabling the re-engineering of fairly loosely controlled emulsions into highly controlled batch-to-batch consistent emulsions (rather than the withdrawal of products that deviated further and further from a low-waste approach) is a key aspect that nostalgic fanboys deny and deny and deny. PX, PXP and PXT shared names, not emulsions. 120/220 PXP and VP were different emulsions. 135 PX and 120 VP shared emulsions, but different anti-halation (which will affect flare) and potentially different hardening regimes (potentially depending on particular coating machine & production melt/ hardening practices - and when those were last revised, relative to equivalent products) - differing hardening will affect behaviour in a tanning developer, and levels of various preservative addenda may impact on stain formation (from my understanding, the 'stain' is essentially a coupler - of unknown long term durability - and levels of things like oxygen scavengers will impact on the relative amount of coupler that can form) - thus a 'professional' grade product may have more effective (but expensive) components added to ensure that its behaviour remains more constant over the lifetime defined by the date stamp.

 

[BMbikerider]

@BMbikerider I should have been clearer, my sarcasm was aimed at those who spend enormous amounts of time and energy accusing Ilford of all sorts of conspiracies that make little sense.

Regarding Kentmere, I think they effectively made only a handful of paper emulsions - Bromide (in 3 grades) - which was probably also Kenthene, Kentona (single grade), and the VC one (one emulsion contrast - but 2-3 different speed emulsions, blended & with ballasted dyes) - and the POP one (which I think came about as the result of a long tail of a nuclear defence product made for the MOD on an RC base). All the 'special' products seem to have largely consisted of a Bromide or Kentona emulsion on different substrates. I suspect that it may have been (too small) market demand rather than outright technical difficulties that stopped Ilford working out how to make Kentona on M14./QUOTE]


Some sarcasm is funny some isn't, Yours was in the former category

There were several other papers which I cannot remember except one that was loved by those who treated their pictures to the Bromoil process. Many claimed there had been nothing quite like it to get the results they were after. If you have not had that process explained it involves making a normal print, washing it thoroughly then bleaching the image. The paper was then soaked again so the emulsion swelled then partially dried off so that the inks were absorbed into the emulsion. When that was discontinued, for some it was as if the world had come to an end.

 

[MattKing]

I've heard this before but I seriously doubt it. The two films printed completely differently. When I first started trying PMK I used both films, the stain on VP was strong, the stain on PXP was weak. Personally I think that VP was Kodak's finest B&W film. I messed around with PXP a bit but never liked it so I find it really hard to believe that they we the same emulsions. They were chalk and cheese.

The anti-halation and substrate differences between late version Verichrome Pan and Plus X Professional meant that they printed entirely differently. They would also account for a difference in staining behavior.
A sales rep working for Kodak Australia would not be likely to know better than the manager in charge of film production in Rochester.
Unless of course, Kodak Australia had a film production line for either film at the time. I'm not sure if Kodak Australia ever made film. I believe Canadian Kodak did at one time. I know that Kodak Ltd. (UK) and Kodak Pathe (France) did.

 

[BMbikerider]

I have done a bit of digging and the factory in Staveley is now trading as Kentmere Packaging Supply, absolutely nothing to do with photography. This makes me ask how or why are they allowed to use the Kentmere logo on the walls because it is a trademark.

 

[DREW WILEY]

At one time, Kentmere Fineprint was their premium netural tone FB VC paper, way ahead of MGIV in terms of quality. It went obsolete once the full trio of MGWT, MG Classic, and MG Cooltone became available under the Ilford label. Harman remains the blanket manufacturing entity name, and makes certain papers for other brands too, like Bergger. Who knows about the packaging business? That's needed for film and paper too; so maybe Harman just leased out part of their facility, and gets a little extra income licensing the Kentmere brand logo as well. Lots of possibilities.

 

[Craig]

This makes me ask how or why are they allowed to use the Kentmere logo on the walls because it is a trademark.

I have a background in Intellectual Property, which includes patents and trademarks. A trademark only applies to a particular type of goods and/or services, the applicant will specify what classes of goods they want the trademark to apply to when they make an application to the government office responsible for trademarks. The Patent and Trademark Office will then do a search to determine if that mark is already in use, and then grant or deny the the right to use the mark.

The mark also has to be used in commerce, which means that you can't have trademark squatters who register something with no intention to offer goods or services for sale under that mark. The patent and Trademark office will consider what classes of goods and services the proposed use is for, and determine if there is a likelihood of confusion in the marketplace. Would an average consumer expect that a packaging supply company also makes film? Probably not, so you could have two companies use the same mark for different goods. Similarly if a company started selling "Ilford Ice Cream" an average consumer wouldn't think that it was the same company that makes photographic materials, as ice cream and film have nothing to do with each other.

Also consider that word marks and symbol marks are not the same. For example, the word Ford in ordinary text and the Ford logo in script within an oval background is not the same trademark.

 

[AgX]

I have done a bit of digging and the factory in Staveley is now trading as Kentmere Packaging Supply, absolutely nothing to do with photography. This makes me ask how or why are they allowed to use the Kentmere logo on the walls because it is a trademark.

It is basically still the same firm ! As I tried to indicate above.

Kentmere over time added manufacture of packaging materials. Later these businesses were split but remained under same Kentmere umbrella, at same place.
Harman later bought the photographic department. Concerning the tradename, Harman has experience in such cases...

 

[BMbikerider]

I have a background in Intellectual Property, which includes patents and trademarks. A trademark only applies to a particular type of goods and/or services, the applicant will specify what classes of goods they want the trademark to apply to when they make an application to the government office responsible for trademarks. The Patent and Trademark Office will then do a search to determine if that mark is already in use, and then grant or deny the the right to use the mark.

The mark also has to be used in commerce, which means that you can't have trademark squatters who register something with no intention to offer goods or services for sale under that mark. The patent and Trademark office will consider what classes of goods and services the proposed use is for, and determine if there is a likelihood of confusion in the marketplace. Would an average consumer expect that a packaging supply company also makes film? Probably not, so you could have two companies use the same mark for different goods. Similarly if a company started selling "Ilford Ice Cream" an average consumer wouldn't think that it was the same company that makes photographic materials, as ice cream and film have nothing to do with each other.

Also consider that word marks and symbol marks are not the same. For example, the word Ford in ordinary text and the Ford logo in script within an oval background is not the same trademark.

I understand what you said about different wording, but the wording is in the same typeface as that on a box of Kentmere film and the logo attached to the sign is also the same as on the box including the colours.

 

[AgX]

Craig just explained that one can split a tradename in use for registered different products, this makes it easy to sell or licence these legal variants.
Alternatively one just can licence a registered tradenname in a contract with certain limitations, without making this public at all.