This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Dippers. For the purpose of lowering the plate into the silver bath, or into the fixing bath, you should provide yourself with two hard rubber dippers. These are so arranged that the plate rests on the small tips attached to the bottom of the dipper. There is still another style of dipper, made of German silver, which will answer every purpose, but it is not generally in use in this country.
Bottles. You should provide yourself with a number of bottles large enough to hold the contents of your silver bath. Two or three of these bottles should be kept on hand, and two silver baths should be prepared - one being placed in the sun while the other is in use. The object of sunning the bath will be more fully described in a later chapter.
879. Besides the large bottles for the silver bath, you should provide a few bottles for your collodion, also for the developer. Collodion bottles should be provided with small necks, permitting of as little area as possible for exposure to the air when the stopper is removed. A small-necked bottle is also more convenient for use in flowing the plate. The developer bottle should be wide-mouthed. The bulk of your stock solution should be kept in very large bottles, while the developer ready for use may be kept in smaller bottles. Bottles should also be provided for your intensifying and reducing solutions.
Glass. A good quality of sheet glass, carefully selected, free from bubbles, scratches and other defects, will answer for the smaller sizes. For large sizes and important work, either flat crown or patent plate-glass should be used. The former is preferable.
Negative Collodion. In preparing the negative collodion, we generally divide the process into two sections. First, we prepare what is known as plain collodion, which is made up of ether, alcohol and negative cotton (gun - cotton). The plain collodion alone is not suitable for negative work, but it must be iodized before it is ready for use. The object of the distinction between plain collodion and iodized collodion is as follows:
882. Where much use is made of the wet plate process, and special results are required for different kinds of work, the formula for the collodion requires changing. In some cases more detail is required, in others more contrast is necessary; consequently, this altering may be done in the iodizing of the collodion. Many commercial users prepare their plain collodion in large quantities and then iodize portions of it for different purposes, and place each in a separate bottle; in consequence, they have different formulae to be used on different classes of work - thus the object of the terms plain collodion and iodised collodion.
Formula For Negative Collodion. Note: For the convenience of the beginner, in the following formula we supply a quantity of 20 ounces of collodion. Any larger or smaller quantity may be prepared in the same proportions: