Storage bottles come in all different sizes and are a requisite component of any darkroom. A sufficient supply, in different sizes, should be kept on site. Like trays and tongs, bottles should be labeled and dedicated to a specific chemical. Some bottles come with a blank area for writing dates and other notations. The labeling of bottles is an important factor when mixing and storing chemicals. It is very frustrating and not worth the aggravation of using chemistry that is outdated or spoiled.
Certain bottles are designed so the excess air can be squeezed out of the stock solution. This prevents unwanted oxidation of the chemistry and prolongs the life of the mixture. Storage bottles should also be opaque to prevent sunlight from affecting the solutions.
Large storage bottles are good for mixing stock volumes while smaller bottles are good for diluting to a working solution.
Smaller bottles are easier to group together for submersion into a water bath in order to bring them to working temperature. Bottles with a handle provide a firmer grip and bottles with a tapered neck allow easier pouring.