I seldom wash a paintbrush choosing instead to store them wet for future use. Being a professional decorator I know I am much more likely to revisit a stored paintbrush than an infrequent home improver, however this technique can be useful for wet storage for as long as a project lasts, saving you time and effort. An additional benefit of paintbrush wet storage is that on commencement of your decorating project there will be no water residue leaking from within the stock, which is likely with freshly washed paint brush which is not fully dried. This simple wet storage method is even beneficial for relativity short periods such as when waiting for paint layers to dry for not only does it keep the paintbrush wet it also keeps it safe form dust and debris contamination.
Simple place your paintbrush in a thin clean polythene bag and wrap the bag around the bristles and stock, expelling any air pockets and place in a cool location. As long as the paintbrush is sealed it will remain wet.
Roller sleeves can also be stored this way. Detach them from the roller arm and place them inside a polythene carrier bag and warp them up tightly. It is best to place the wrapped roller sleeve inside a second bag as sometimes they have small holes and any exposed roller pile will harden and ruin the roller sleeve. Remember to and place the wrapped sleeve in a cool location