My thanks to Paul Godfrey for telling me of information by Jack Coote, written in his "Illustrated History of Colour Photography". (Jack Coote was Head of Technical Services for the Ilford Group during the 1970s and later became Technical Advisor to the Head of Marketing.)
"In 1952 the Photo Chemical Company, operated by Dr. K. Jacobson and Dr. White in the UK, launched the Pakolor negative-positive process in conjunction with Associated British Pathe, the motion­picture production company. Pakolor film, based on Agfa technology, was coated by Standard Photographics of Leamington, while the paper was produced by Kentmere at Staveley in the Lake District. The colour couplers and other special chemicals were supplied by the Photo Chemical Company and the film processing kits incorporated a combined bleach-fix for the first time".

Although Pakolor negative film was originally only balanced for daylight, by 1953 it was available in two types, daylight and artificial, both of speed 15ASA and both available in roll, cut and 35mm film formats. The 1952 AP review said the film was rated at Weston 12 (around 15ASA) but they found this a bit excesive and suggested Weston 8 for general work (10ASA) "bearing in mind that slightly full exposure is more tolerable than slight under-exposure, and that colour film is too expensive for one to risk failure lightly." The 10ASA speed recommendation seems to have been adopted by Pakolor, as 10ASA is often quoted as the film speed in subsequent references (see the BJPA 1955 test).

Amateur Photographer credited Pakolor's technical development to Dr.C.I.Jacobson though strictly the originator was Dr.K.I.Jacobsohn, as his name was Kurt Israel Jacobsohn. He came to England, with his wife, from Nazi Germany in 1939.

"it is intended eventually to release processing instructions or kits, and also printing paper, so that any amateur can develop his own films and make prints and enlargements in full colour in his own darkroom."

Amateur capacity procesing was possible by the end of 1954, when kits containing chemicals, paper, a special safelight, three (additive) printing filters and an instruction booklet, costing £3.7s.9d (£3.39p), went on sale. These outfits were manufactured and packed by Johnsons of Hendon. Modern Camera Magazine (MCM) for May 1955 carried an announcement that "Mr R M Reed of Associated British-Pathe has prepared a most interesting lecture, fully illustrated with colour slides, on Pakolor home processing and printing, and his lecture is available to accredited clubs and societies on request."

The 1956 BJPA (p217) report of the Pakolor Processing and Printing Outfit No.1.

"This modestly priced outfit contains all that the beginner in colour photography needs to make a start with a negative-positive process.

The colour developer chemicals are supplied to make three stock solutions which are mixed in different proportions to suit either the film or the paper. A combined bleach and fixing solution is used which keeps the total processing time reasonably short with both paper and film.

One interesting modification is the hardener-stabiliser which was not formerly supplied with the kit but had to be made up by the user from formaldehyde solution. This solution is now supplied as a dry chemical which is dissolved in water in the usual way to make the working bath.

The tricolor filters which are an essential feature of the Pakolor printing method are mounted in a simple card mount which slides in a shaped wire holder fitting over the enlarger lens.

The developing solutions are supplied as two packets, one containing the chemicals for the developer and the other for the stop bath, bleach-fix and hardener stabiliser solutions. Part 1 contains sufficient to make 80 fluid oz (2litres) of working strength developer for either film or paper, and Part 2 con-tains sufficient to make 21 fluid oz (600c.c.) of the other solutions, which can, of course, be used repeatedly. In addition to the chemicals and the filters the outfit contains a packet of ten sheets of Pakolor paper size 3½ x 4½ inches and a 5 x 7 inches safelight screen. The kits are manufactured and packed by Johnsons of Hendon Ltd., for Photo Chemical Co., and cost £3. 7s. 9d. complete.

Further supplies of the separate Part 1 and Part 2 kits may be obtained separately, Part 1 costing 9s. 6d. and Part 2 costing 7s. 6d."

The 1956 BJPA also compares results from the three colour negative films then available in the UK.

"The best resolution is obtainable from the Gevacolor process, and this is also capable of the reproduction of red with an almost dye transfer quality, coupled with a good generall overall fidelity of colour reproduction. Agfacolor material, in the writer's experience, is most consistently reliable, and although the reproduction of red is not as brilliant as with Gevacolor, the quality obtainable using Agfacolor material can be extremely good. Pakolor, as one may perhaps expect of a process comparatively new, tends to suffer rather from inconsistency and emulsion coating faults, although the process does not appear to enjoy the entire monopoly of this type of fault. The fidelity of reproduction can be very good, but with some tendency to exaggeration of certain colours, particularly blue. In the separation of colour it can be superior to either of the other two processes, at some expense of contrast."

In 1959 Pakolor materials (by then distributed from Pakolor Ltd, Epsom, Surrey) was advertising "Everything for Colour" via their 'Double U' system "enables the photographer to print and enlarge from all makes of colour negatives by easy stages." "..begin with a simple Colour Processing Kit and add ... according to... requirements." Home printing kits cost FROM £1 13s 5d (£1 67p).

Pakolor paper was also available for direct reversal printing of colour transparencies, 20 postcard sheets cost 14/6d (72.5p) and a processing kit cost 18/- (90p). A trial outfit including filters cost 48/8d (£2 43p).

The 1959 price of a kit to develop Pakolor Super 40 (ASA) colour negative film was 17s/6d (88p), but presumably it processed several films as commercial film developing only cost 6s/6d (33p).

The BJPA for 1960 describes the use and processing of Pakolor Paper Type DRP, being "a three-layer paper designed to make colour prints directly from colour transparencies, and Pakolor Paper Type FC, being "a three-layer paper available in two grades, normal and hard, primarily intended for printing from Pakolor colour negatives. The recommended printing technique for Type FC paper was to make three exposures through a set of special tricolour filters (i.e. an additive printing method, as the subsequent Paterson-Pavelle process)

Pakolor was still appearing in Amateur Photographer magazine at the end of 1960, with P.S.Color Services of Croydon advertising the Pakolor Three Filter Method Negative Positive Outfit "NP" for £2.15s.7d and an outfit for printing from transparencies, the "TR" outfit, costing £2.7s.9d. The 40ASA Pakolor print film was included in AP's 'Outdoor Number', 7th March 1962. A 620/120 roll film cost 8/3d (41p), developing cost 6/6d (32.5p) and en-prints (2¼"x4½" or to negative shape) cost 2s (10p). Pakolor was also available in a 12exposure casette for 8/3d.