The thumbnail version:
- Ideal coating and drying conditions conflicts with washing out
- There are solutions
The full version:
You don’t want unexposed emulsion to be exposed to light, whether it’s on a coated screen prior to exposure or on an exposed screen prior to washing out. So usually in both instances the coating and drying and the washing out occurs in a single darkroom.
The downside to this is that washing out creates a humid atmosphere which is less than ideal for the coating and drying process. The solution? Two darkroom spaces or some similar arrangement that separates the humid air of the washout area from the drier air of the coating and drying area.
If building a second darkroom or creating two darkroom spaces within your existing darkroom is not possible for some reason, a way around the issue is to do your coating and drying at a different time from your washing out. For instance, you could do your exposing and washing out in the morning and then coat screens later in the day for drying overnight.