Postal letter templates can be customized in Account -> Set up -> Email Templates. You can use any generic template.
See flash tutorial, Using Email Template to Print Postal Letters for detail.
The complete HTML code for this sample letter is in the attachment.
This letter has a image at the top of the content. This is done with the following HTML code:
Pictures/Logos:
<td align= center ><img src= http://www.ebsuite.com/servlet/BbsFileServlet?fileid=1870&filekey=rFoCEOfw >
<br><br>
</td>
The align= center parameter places the image as center justified. The source of the image is stored in the EBSuite system. To store your images, upload the images as an attachment to a note anywhere in the system. To find the path simply right click or control click (Macintosh) on the URL to the image. Then copy/paste your link with the link above.
Fonts:
The HTML code uses style sheets to set the parameters for fonts. You may edit the style sheet definitions to change the fonts. Using CSS, you can add and change the fonts and styles, style2, style3... Below is the style sheet code:
