1. Do not disturb the deposit which will occasionally be found at the bottom of the bottle containing the collodion.
2. Remove all particles of dried film from the neck of the bottle before pouring the collodion on the plate.
3. Never use damp cloths, leathers, or buffs, for giving the final polish to the plate. Negatives with an indistinct and muddy surface are frequently produced from this cause.
4. Let the film set properly before immersion in the nitrate of silver bath: its condition can be ascertained by gently touching the lower part of the coated plate with the end of the finger.
5. Never omit to pass a broad camel-hair brush over the plate just before pouring on the collodion.
6. Bear in mind that, as light is the producing agent, so will it prove a destructive one: not less than four folds of yellow calico should be used to obstruct white light; and in that case the aperture covered should be no larger than is necessary to admit sufficient light for working by. Examine occasionally the yellow calico: when this material is used to exclude white light, it becomes bleached by constant exposure. Do not trust alone to any coloured glass; no glass yet made is anti-actinic under all aspects of light and conditions of exposure.
7. When the negative requires intensifying, carefully wash off all traces of the first developing solution before proceeding to intensify. This operation may be performed either before or after the iodide is removed by fixing.
8. Glass baths are preferable to porcelain, ebonite, or gutta-percha baths for solution of nitrate of silver.
9. In using either spirit or amber varnish, before pouring it off, keep the plate horizontal a few seconds. This gives time for soaking in, and prevents the formation of a dull surface arising from too thin a coating.
10. Rub the lenses occasionally with a soft and clean wash-leather; the rapidity of action is much influenced by the brightness of the lenses: their surfaces are constantly affected by moisture in the atmosphere, which condensing, destroys the brilliancy of the image.