Tag: Ferrania

Summary of Film Elements and Condition Report

Tait Collection Acquisition No. A1060

Calypso (1952-7)

Can 37: Roll 1: Original ‘Mezzo-bande’ optical soundtrack, 17.5mm.

Roll 2: Hand-painted master positive, 35mm, Comopt, 404ft, 1952.

Roll 3: BBFC Certificate title, 35mm, 1957.

Can 38: Reversal reduction print from original,16mm, Comopt, 156ft, 1958.

Can 39: Colour print of can 37#2, 35mm, Comopt, 404ft, 1958.

Summary of Film Elements and Condition ¹

Can 37, Roll 1 is the original Italian soundtrack given to Tait in 1952. The stock is cut-down 35mm optical stock, commonly used in Italy at that time for recording optical soundtracks in the process of ‘building up’ multiple tracks. The stock is marked ‘FERRANIA S.A.V’, indicating the Italian film stock manufacturer, Ferrania. Edge marks are in black.

Can 37, Roll 2 is the original film painted by Tait in 1952 with assistance from Hollander. It is a 35mm black and white Kodak optical stock printed from Roll 1. Tait has painted onto the emulsion side of the clear stock with dyes of several different colours (see below for lengthy discussion about the dyes used). The film stock has a light but thorough covering of fungus throughout as do many of the films in the collection. The emulsion is badly cracked and the film appears to be shrunk. British Kodak Safety stock dated 1952. Sound quality is good.

Can 37, Roll 3 Original black and white BBFC, Certificate ‘U’. Verification of this can be found on the BBFC online database. British Kodak Safety Stock, dated 1957.

Can 38 contains a 16mm Kodachrome reversal print direct from the 35mm painted original. Colours are relatively close to the original although they have suffered somewhat during the printing and possibly over time. On the whole, the background washes of colour have become fainter and there is a lack of definition between the blue and green. The film is scratched throughout including tramlines. There is some emulsion cracking and fungus. The sound is on a variable density optical track and poor. The can also contains a card: ‘FILMS and BALLADS in the Temperance hall, Kirkwall on Monday, 29th October at 8pm. ADMISSION 2/6 (Inclusive of Duty)’.

Can 39 is a print from the hand-painted original (Can 37 #2) onto British Kodak stock dated 1958. It also includes the BBFC Certificate which can be dated to 1958. The colours are inverted from the original (i.e. the clear background is now a black/magenta) and are predominately magenta and a yellowy green. The film is acetic and shrunk in parts as well as having fungus and some abrasions and perforation damage. All the vivid colour of the original has been lost.

Notes on The Preservation of Calypso

Hollander has said that the original film was never meant to be projected and that 16mm reversal reduction prints (like #38) were the intended projection medium. ² He is in possession of one of these prints, others were made at the same time and Tait had one made in 1958. However, this still leaves the 35mm print in can #39 which appears to contradict Hollander’s recollections. He has said that they had no access to a 35mm system in Italy so it is possible that Tait had a print made as an experiment once she returned home and had access to the equipment. The print is completely different to the hand-painted original and the Kodakchrome print yet it does have a BBFC leader and shows signs of possible projection wear.

The hand-painted original was painted with water soluble dyes and has fungus and cracked emulsion. Normal cleaning and printing methods which commonly use the chemical Perchloroethylene would almost certainly remove the colour dyes. On a recommended alternative cleaning method, see below.

On Dyes

Researching the dyes used by Tait has been the most fascinating aspect of my research. I am now quite certain that the dyes Tait used to paint Calypso (and Painted Eightsome and John MacFadyen) are dyes used in the profession of Pathology or more precisely, Histology. These are dyes that are commonly employed as stains in biological laboratories. I have come to this conclusion due to the following reasons:

• Mike Leggett’s conversations with Tait in the 1970s show that at that time she referred to the dyes as ‘aniline dyes’.
• Len Lye is known, for example, to have used ‘aniline dyes’ to paint on film. ‘Aniline dye’ is also a commonly used term in the tinting of early silent films. Not all these dyes were the same or even similar. The term, ‘aniline dye’ is used generically to refer to an ‘artificial’ or ‘synthetic’ dye.

Because the first artificial dyes were produced from aniline all of this class are often called “aniline dyes,” although there are now a large number of them which bear no relation to this compound and are not derived from it. Therefore the term is now quite largely being replaced by the more correct expression “coal-tar dyes,” since all of them are made by chemical transformations from one or more substances found in coal-tar. ³

Hollander recalls the dyes being “medical dyes”. ⁴ As I have noted, ‘medical dyes’ refer to dyes used in Pathology which are also generically referred to as ‘aniline dyes.’

Tait was a qualified Doctor. She would have been aware of such dyes, had experience with their medical application and would have known how to obtain them.

Having come to this conclusion, I searched for information on medical stains. A good reference is available on the internet ⁵ and referred me to a classic text, H.J.Conn’s Biological Stains. It is an overwhelming topic for the inexperienced so I contacted Bryan Llewellyn, a Histotechnologist ⁶ who was able to offer advice.

Acknowledging my subjective interpretation of the colours Tait used to paint Calypso and that they may have changed with age, I described them to Llewellyn based on the SFTVA Technical Records and my own observations: black, warm ultramarine blue, green-blue, acid lemon yellow, warm yellow, purple, vivid viridian-green, bright leaf green, pink-alizarin red, red, and green-brown. I also told him that the dyes were probably obtained in Italy around 1951. From this, Llewellyn suggested that the following may have been used by Tait: ⁷

• black – Amido black 10B, sudan black B. If it is pure black it may be India ink.
• warm ultramarine blue – Aniline blue, or one of its constituents.
• green-blue – Alcian blue.
• acid lemon yellow – Picric acid, martius yellow, metanil yellow.
• warm yellow – Orange G.
• purple – Methyl violet.
• vivid viridian-green – Fast green FCF.
• bright leaf green – Light Green SF yellowish.
• pink-alizarin red – Phloxine, rose bengal, mercurochrome or another homologue in this series. It could even be alizarin with some calcium added.
• red – Acid fuchsin, basic fuchsin.
• green-brown – This presents a difficulty. There is only one brown dye that comes to mind – bismarck brown – but that is pure brown. Perhaps this is a mixture of two dyes, mostly brown with a touch of some green dye.

Llewellyn’s last comment highlights the greatest problem of subjective descriptions of colour: Tait may have modified the dyes by mixing them. He suggests first contacting a histology laboratory and asking for a small amount of each dye they stock. With these, solutions could be made up and used to paint on a test piece of film, comparing the colours and checking for synonyms and homologues in common use in H.J. Conn’s text. Having done that, a more accurate analysis of the dyes used by Tait would have to be done using a spectrophotometer; the former subjective test results would then be used to broaden an understanding of these laboratory tests.

A spectrophotometer is the preferred method of testing dyes over chemical analysis because the detailed chemistry of some dyes is obscure and “the reactions are often complicated by adulterating dyestuffs in such a manner as to preclude entire reliance on rigorous chemical methods. Often a slight change in the arrangement of atoms within the molecule will make a marked change in the nature of the dye, while such a minor change in structure is not always readily detected by chemical means alone.” ⁸ A spectrophotometer would reliably detail the characteristic absorption spectra of each dye.

Quantatitive as well as qualitative data may be obtained by the spectrophotometer; from the combined results nearly all dyes, even though differing from each other only in very minor particulars of chemical structure, may be easily differentiated. This method is not only rapid but is also convenient. ⁹

Recently the SFTVA has carried out a number of tests with several different paints, dyes, and inks but were unable to reproduce exactly the same effect Tait had achieved using the ‘aniline’ dyes. Usually, because of the transparency of the dyes, colours which seemed similar to the original under reflective light were quite different when shown with projected light. In contrast, the method of testing by spectrophotometer “depends upon the fact that any coloured substance absorbs light of certain definite wavelengths and transmits the rest.”

The absorption spectrum is essentially the inverse of that which is transmitted. Therefore the colour of light which reaches the eye after transmission through a coloured substance is complementary to the colour of light absorbed by that substance. A violet dye, for example, appears that colour because of its predominant absorption of greenish yellow light. The absorption maximum is quite characteristic of any dye; any two dyes having the same absorption curve (a somewhat rare occurrence) are of essentially the same colour. ¹⁰

The basic advantage of the spectrophotometer is fairly obvious but where its use is particularly advantageous is for analysing dyes which may be impure mixtures of more than one dye. Whereas the eye is unable to distinguish between, say violet and the same mixture of red and blue, this heterogeneous character of the mixed dyes can be easily identified with the spectrophotometer because it is able to reveal differences in the character of the light absorption of each dye used.

Typically, the dyes used for medical applications can be categorised by their solubility in water and alcohol. ‘Alcian Blue’ for example, perhaps the ‘green-blue’ noted in the Technical Records for Calypso, has a solubility in water of 9.5% at 15° C and a solubility in alcohol of 6.0% at 15° C. ¹¹ Such data would be useful when determining how the film might be cleaned. The SFTVA have tested the water solubility of small samples of dye from Calypso. Dye that had been brushed into the perforation area was rubbed with a damp cloth which removed the dye, thus proving that particular dye was water soluble. In all probability, this will be typical of every dye used because unlike Len Lye, Tait does not appear to have rubbed off the excess dye after she had painted and applying water to it today would remove the surface material and thus the density of the dye. ¹² Having the results from tests using a spectrophotometer would, of course, make this test much more qualifiable.

On Mould

The treatment of mould on photographic materials is a widely discussed area in the Archiving profession. ¹³ When dealing with mould in a collection, three basic issues must be addressed:

• The health and safety of staff.
• Arresting the further growth of the mould.
• The removal of mould from the collection altogether.

The mould on the Tait collection is quite widespread and appears as a fine white-grey coating over the film emulsion. Fungi thrives by feeding on the gelatine in the emulsion causing permanent damage to its transparency. Read & Meyer describe gelatine as organic proteins found in animal skins and bones and when solidified into a gel provide flexible and consistent support for the photographic silver bromides. They also contain active impurities which improve the light-sensitivity of the metallic salts. ¹⁴ It is thus incidental that they also nourish and support fungus and bacteria. A severe case of fungus (which I don’t think the Tait films suffer from) can easily gouge troughs in the emulsion surface resulting in a visible etching which may consequently show up on duplications. Because mould affects the physical and chemical structure of the film it can also alter the colours of dyes and even if the covering of mould on the Tait films can be removed, it is likely that the colours would already have been affected. From my observations, however, the colours in the Tait films remain bright and vibrant and do not seem to have altered considerably. Once the dyes are known, this can be verified.

Mould germinates and grows when the relative humidity reaches or exceeds 70-75 percent and remains so for several days.

High temperatures, poor air circulation, dim light, and accumulated grime assist and accelerate the growth of mould once it has germinated, but only high relative humidity and moisture contents of the substrate can initiate and sustain mould growth. If the relative humidity drops below 70 percent and the materials lose their high moisture content to the atmosphere, these moulds will stop growing and become inactive or dormant, but the spores will remain viable on the host material. They will become active and begin growing again if the relative humidity rises. ¹⁵

This explains why presently the fungus on the Tait films appears to be ‘dusty’ and inactive since the removal of the collection from Tait’s Orkney studio to the controlled storage facilities of the SFTVA would have affected the conditions under which the mould was thriving. The cool storage and low humidity of the Archive is ideal for keeping mould dormant.

Although Read & Meyer provide a brief discussion on the common treatment on films with mould, much of it is quite inappropriate for the Tait films because of the dyes she used. They recommend inspecting the mould growths under a microscope using a needle to probe the image area to see whether the mould is on or below the surface of the film. This could certainly be recommended with the Tait films as would consultation with a Mycologist to identify the mould species present. Next, if the emulsion is firm, they suggest that the film should be rewashed which usually removes surface growth and cleans out any grooves cut by the fungi. Clearly this could be disastrous for the Tait films since it is quite certain that some, if not all, of the dyes are water soluble. The next stage they discuss is minimizing the effects of mould during printing. They write that wet-gate printing would have the same effect it does on scratched film: filling in the grooves with the liquid, Perchlorethelyne which has a similar light refractive index as film. In other applications, Perchlorethylene is mainly used as a solvent and its use with the Tait films could not be recommended at this stage nor any other wet method of cleaning or printing. Finally, Read & Meyer discuss the prevention of further growth using biocides. Again, these are liquid-based and cannot be recommended at this time.

The use of biocides relates to the first of the three stages listed above. Much has been written about the treatment of mould in a collection and repeatedly, health and safety warnings are first and foremost included.

There is no easy way of responding to mould outbreaks on collection materials. Because the metabolism of fungus is much like our own, what is deadly for mould can also be dangerous for us, e.g., ethyline oxide effectively kills mould but is not safe for humans. And because the presence of mould can also be harmful to people, knowledge of and adherence to safety precautions is imperative. ¹⁶

The SFTVA is fairly well equipped to deal with fungus on films and correct safety measures could easily be adopted. Films in the Archive infected with fungus are isolated to particular viewing machines and work spaces are cleaned after these films are handled over them. Although suggested by Read & Meyer, biocides are generally not recommended by many Conservators because of the potential risk they impose to staff. Their use can also be quite restrictive and highly regulated. Read & Meyer do state that anyone handling infected films should wear gloves and a full nose and mouth mask with a filter capable of trapping particles down to 4 microns. Movement of the films should be kept to a minimum to avoid infecting other areas of the archive and should remain in their container until needed. In cases where biocides are used, recommendations for handling and use should be followed, in particular, the provision of adequate air extraction.

By far the most popular choice for the removal of surface mould on delicate materials is the use of a special vacuum ¹⁷ fitted with a HEPA filter. This method is simple to carry out and relatively safe and avoids spreading or further embedding the mould into the film emulsion. With this method, the surface of the film is simultaneously brushed and vacuumed. The HEPA (High Efficiency Particulate Air) filtratration is certified to trap 99.97% of all airbourne particles larger than 0.3 microns which includes fungi, ¹⁸ ensuring that the mould is not redistributed within the Archive and can be emptied outside. Although great care should be taken when vacuuming, once tests with a soft camel-hair brush have been carried out they are likely to show that the films can be brushed quite firmly. Vacuuming should be alternated with aeration provided the air is below 60 percent relative humidity. Good ventilation and air extraction should obviously be a priority, too. The SFTVA already has a cleaning room with exceptional air extraction.

Clearly, the issues of mould and dyes are of primary importance to the preservation of all the hand-painted films. Here I have gone into just the necessary detail to indicate what the SFTVA might attempt when they approach the restoration of the Tait films. Although it is perhaps an unusual procedure, the hand-painted films are not only unique to the Archive’s collection but also unique objects in themselves and traditional restoration and preservation techniques cannot be entirely relied upon.

To summarise: in order to make good preservation copies, the films first need to be cleaned. To safely clean the films, the particular types of dyes applied should be understood. Meeting both these prerequisites, will establish a reliable colour reference necessary for printing. Likewise, successful, restorative printing depends on knowing which dyes were used and on successfully removing the mould. Failure to remove the mould may affect whether the dyes can be accurately determined. Because of the centrality of these two issues, consulatations with a Mycologist and Histotechnologist are highly recommended.