Design for the Use Environment
 
When you plan your manual, think about how and where it will be used.  If your company makes fax machines, you can be fairly certain that the person reading your manual will be sitting at a desk in an office with good lighting.  But what if your company makes farm implements?  The user might be in a dimly-lit machine shed or under bright sunlight in a hayfield.  Either way, you’ll probably need to make the font a bit larger.
 
Lighting isn’t the only thing to consider.  Will your users have clean hands?  Not if your product is industrial machinery.  Consider using coated stock for pages that will be referred to often—such as in maintenance manuals.  Will the user be referring back and forth between manual and product as he or she performs a procedure?  Make sure the pages will lie flat without the user having to hold them in place.  The more you research the use environment, the more useful you can make your manual—and the more likely it will be to be used.