Occasional headers

Is it possible to set particular documents to print headers or not to print them?

I like to have headers on articles and fiction, but would prefer letters not to tell their recipients that they’re a Scrivener document - it doesn’t quite look professional. But how do I stop the header printing on letters, invoices and so on, without removing them from everything else too?

File > Page Setup > Settings > Scrivener. Also, note that File > Print is really intended for rough drafts; File > Compile Draft > Print is intended for proper formatting, and allows more control over headers/footers etc. Generally, Scrivener isn’t designed for writing letters - it’s not very good at that. For letters, I’d always choose a dedicated word processor/layout program, such as Nisus, Pages or Word.
All the best,

Hm. Yes. But it’s handy to have work letters - for instance, invoices and their cover letters - in the same project as the work that I’m invoicing for.

You can keep external documents related to a Scrivener project in the same folder as the Scrivener project and link them to the project as project references. Your question implies that you use one Scrivener project per work project. I don’t. For one work project, I frequently have two different Scrivener Projects open at the same time-usually an earlier draft and a rewrite. I keep letters, meeting notes, corespondence, email, contract copies, web site links, and other miscellany about the work project in Journler or in the work project folder. Aside from the fact that Scrivener is not intended to be a polished formatter, it is a very poor program for managing work project documents, not was it intended for that purpose. It cannot sort on dates, for example, and it’s not possible to view more than two internal documents at one time.