How to make a Thunderbird Template using an allover background with a table

Start a new message via File - New - Message (Don't click the Write icon unless you've just opened Thunderbird and haven't used a Template before this)  

Once you're in the new message window, click inside the text area so that the Format menu will become available.  Then click Format - Page Colors and Background. 

 

Choose file.  Here's corkboard.jpg.  Right-click to save a copy.  

Click OK.  The background tiles all over the message window. 

From the menu at the top of the message window (beneath the subject line) click to insert a table. 

Make the table with one row, one column, 90% of the window and no border.  Click OK. 

The table appears, just a long rectangular box at the top of your text area.  Double-click inside the box and the Table Properties options box will come up.  Make the Table Alignment Center.  Make the Background Color a good color for your text to go on.  Make the Cell Padding a bit more than it was.  Click OK. 

It looks a little funny when you're writing the message but when it sends it will look fine. 

 

In the subject line, give the Template a name that will help you remember what it is, like "Corkboard with Post-It"

Click File - Save As - Template

And there it is!  To compose a new message, just double-click on the subject line of the Template you want to use. 

It looks spiff when you send it, but unfortunately if there's a reply it will go on the background rather than in the table.  Be sure to pick a background image that will normal text will be readable with.