1055. Caution

Caution. So delicate is the nature of the Auto-chrome plate, that in a wet condition the slightest touch will cause abrasion, which is irreparable. It is, therefore, advisable to handle the plate as little as possible. The use of glass dishes will be found to reduce the risk of damage, and will also save time, as it will not be necessary to take the plate out of the dish to inspect it. The whole of the manipulations, with the exception of Nos. 3 and 13, (see Table of Manipulations) may, with advantage, be carried out in one dish.

1056. Special Note

Special Note. All solutions must be used at a temperature of 60° to 65° Fahr.

1057. Having prepared the developer A and B in two separate vessels, do not mix together until the last moment, when the plate is in the developing dish; then pour developer onto the center of the plate and keep the dish rocking during the whole time of development, which is complete in two and one-half minutes. The developer must then be poured away and water immediately poured from a jug onto the plate, without removing it from the dish; fifteen seconds' washing - three quick changes of water - will be sufficient.

1058. Now transfer the plate to a bath of C reversing solution for four minutes, when it may be examined by white artificial light. If, on looking through the plate, any semi-opaque patches appear, it must be returned to the reversing bath for a minute, or until the patches have dissolved out. The plate is then put back into the first dish and washed with six or eight changes for half a minute, when it is ready for re-development with D solution. Redevelopment must either take place in daylight or in the light of an electric arc or bright incandescent gaslight. In either case the plate must be exposed to the light, for a few seconds only, before pouring on the amidol developer; otherwise, shadows will appear along one or two sides of the picture, often cutting off part of an important feature in the scene. The positive image is usually fully developed in three minutes, but it is highly important that development shall be carried as far as possible. Now wash for half a minute and pour on E solution. It is important that this solution shall be allowed to act for eight to ten seconds only, or the finer details of the picture will disappear. Wash away immediately, giving four good changes of water.

1059. If the picture is sufficiently bright and clear at this stage it may be considered finished, and dried without any further treatment; but usually, when using the foregoing series of formulae, it will be found that the picture is much improved by intensification. This is done as follows: The F solution is first measured out and poured onto the plate, then the G solution is measured out and added to the F by pouring into one corner of the dish. Intensification may be carried on until the solution becomes turbid; and it may sometimes be even necessary to treat with a second new bath of intensifier; after which wash for half a minute, and treat with the clearing solution H for one minute. Should a trace of green fog appear on the surface, or the whites become tinted yellow, treat with a second bath of H solution. Wash for half a minute and transfer to the fixing bath, I, for two minutes, afterward giving a final washing for five minutes. If great reduction of density takes place in the fixing bath, the time of redevelopment may be extended even to five minutes. The picture will, however, fix out if it has not been sufficiently exposed to daylight or other strong actinic light during re-development.

Where not otherwise mentioned, the solutions must only be used once.

1060. In the various washings it is not advisable to allow the water to fall direct from a service tap onto the plate, as trouble may arise from frilling at the edges, or even in the middle of the plate. If the water is poured on from a jug, as previously suggested, the film is not so likely to frill.


1061. The following table will be found useful in practice, in order that the various quantities of solutions and necessary time of action may be seen at a glance.





In the Dark Room

A, 2 drams



B, 2 " Water 2 1/2 ounces

2 1/2 mins.

All solutions to be 6o° to 650 Fahr. Mix developer at last moment.



15 to 20 sec.


Dissolving the deposited image

C, Sufficient to cover well

4 mins.

This bath will do for three plates if treated at one time.



1/2 min.

In Daylight



D, 3 oz.

3 mins.

Must be done by bright, actinic light, daylight for preference.



1/2 min.


To oxidize developer

E, 3 oz.

8 to 10 sec.

Wash off quickly or quality of picture will be impaired.



1/4 min.



F, 3 oz.

G, 2 drams

2 to 4 mins.

Intensification is the only personal feature in these manipulations, and may be carried as far as may be judged to be sufficient.



1/2 min.



H, 3 oz.

1 min.

Use a second bath if green fog appears on film.



1/2 min.

Care must be taken that no acid permanganate remains "in the film, or it will act with the hypo as a reducer.



I, Sufficient to cover well

2 mins.

In hot weather a few grains per oz. of chrome alum may with advantage be added to the hypo solution.



The above quantities are sufficient for a 5x7 plate

5 mins.

Although the time of washing seems very short, it has been proven to be sufficient. It is found that over washing reduces the colors and causes a pink tone to develop all over the picture.

1062. When Autochrome plates first came upon the market, they were pre-disposed to frill immediately after being treated with the C solution; but it would seem that certain improvements in the manufacture have somewhat remedied this evil, for no such trouble has been experienced with later supplies. It will, however, be useful to have the knowledge of a few expedients, which will assist us to remedy the evil to some extent, should it at any time be necessary.

1063. First. In the absence of suitable materials and apparatus the following may be tried: Absorb the superfluous moisture from all the edges of the plate, by standing them repeatedly upon a folded piece of absorbent blotting paper, and dry as quickly as possible by waving about in the air, or by placing the plate in a current of cool air until dry. This must be done immediately after the frilling commences - at whatever stage after reversal it may appear. When the film has once dried, frilling is not so likely to recur; but if a little celluloid varnish is painted around the edges of the film before re-wetting, no further trouble may be expected.

1064. Second. In a metal dish, melt sufficient resin, one part, and beeswax, two parts, to cover the bottom of the dish to the depth of one-fourth inch. Before commencing to develop, dip the edges of the Autochrome plate into this wax bath, and allow to set before pouring on developer.

1065. Third. Fix the plate in a "whirler" and revolve rapidly until dry, after which coat the edges with a varnish of wax or celluloid.