One of the paper size options in the DeskWriter Page Setup (or DeskJet Print Setup) dialog is Envelope. When this size is selected, MacWrite II and ClarisWorks set the top and bottom margins to .38". However, the DeskWriter has a minimum bottom margin of .57". If you try to print, you will get the message: "The bottom margin is smaller than the minimum allowed by the printer. The document may be clipped."
The solution is to set the bottom margin for .57" or larger. To avoid having to do this step each time you print an envelope, create a stationery document with the correct settings and open it whenever you want to print an envelope.
Printing using Envelope Assistant (Version 3 and 4)
When using the Envelope Assistant to a Deskwriter 600 series printer, the resulting word processing document has the left margin at 0.31. When you print, the first character or so is not printed. To print correctly, increase the left margin to 0.453 or greater. (This may also happen with other Deskwriters and/or versions of the DeskWriter driver).
To avoid having to do this step each time you print an envelope, save the file (with a blank addressee) as a stationery file. You can later open the stationery file, fill in the addressee, then print.