Thanks Amy2203, I looked through order_invoice_print.tpl, and found that it calls
mail/html/order_invoice.tpl
and then just added the word 'TEST' in the middle of one of the lines of data in the invoice, and it appears in both - so it uses the same template! I feel such a fool.
I should have noticed all the
Code:
<td {if $is_nomail eq 'Y'}class="invoice-line"{else}height="4"{/if}><img src="{$ImagesDir}/spacer.gif" {if $is_nomail ne 'Y'}style="height: 2px; width: 100%; background: #58595b none;max-height: 2px;"{/if} alt="" /></td>
throughout order_invoice.tpl. Now I know what I'm doing, I just need to change the properties after the {if $is_nomail eq 'Y'} to what I want, and it will appear on the printed version, but not the screen version.
So I can add printed version only text, etc. by putting
{if $is_nomail ne 'Y'}<h2>Printed version</h2>{/if}
etc.