From my 3.5
/mail/html/order_invoice.tpl
Code:
<html>{* $Id: order_invoice_html.tpl,v 1.9.1ADP 2004/07/07 12:40:11 ADPBoss Exp $ *}
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="8" align="center" valign="top"></td>
<td align="left" valign="top">
<font size="3" face="Verdana, Arial, Helvetica, sans-serif">
{$lng.lbl_invoice_sdinfo1}</font></p>
</td>
<td width="250" valign="top"><p align="right"><font size="2" face="Verdana, Arial, Helvetica, sans-serif">
{$lng.lbl_invoice}: # {$lng.lbl_order_prefix}{$order.orderid}
{$lng.lbl_order_id}: #{$order.orderid}
{$order.date|date_format:"%d.%m.%Y"}
{$lng.lbl_gst} #: 85550 0732
</font></p></td>
</tr>
</table>
<hr size="1" noshade>
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr valign="top">
<td nowrap><font size="2" face="Verdana, Arial, Helvetica, sans-serif">{$lng.lbl_bill_to}:</font></td>
<td width="50%">
<font size="2" face="Verdana, Arial, Helvetica, sans-serif">
{$order.b_firstname} {$order.b_lastname}
{$order.b_address}
{$order.b_city}, {$order.b_statename}
{$order.b_countryname} {$order.b_zipcode}</font><font size="2">
<font face="Verdana, Arial, Helvetica, sans-serif">{$lng.lbl_phone}: {$order.phone}</font>
<font face="Verdana, Arial, Helvetica, sans-serif">{$lng.lbl_email}: {$order.email}</font></font>
<font size="2">
</font></p></td>
<td nowrap><font size="2" face="Verdana, Arial, Helvetica, sans-serif">{$lng.lbl_ship_to}:</font></td>
<td width="50%"><font size="2" face="Verdana, Arial, Helvetica, sans-serif">
{$order.s_firstname} {$order.s_lastname}
{if $order.company ne ""}{$order.company}
{/if}
{$order.s_address}
{$order.s_city}, {$order.s_statename}
{$order.s_countryname} {$order.s_zipcode}
{$lng.lbl_phone}: {$order.phone}</font></font>
</td>
</tr>
</table>
{include file="mail/html/order_data.tpl"}
</html>
Keep in mind I have Custom Language variables in there.
/main/order_invoice_print.tpl
Code:
{* $Id: order_invoice_print.tpl,v 1.4.6.3ADP 2004/07/14 18:32:01 ADPBoss Exp $ *}
{if $config.Appearance.print_orders_separated eq "Y"}
{assign var="separator" value="<DIV style='page-break-after:always'></DIV>"}
{* else *}
{* assign var="separator" value="===============================================================================" *}
{/if}
<html>
{section name=oi loop=$orders_data}
{ include file="mail/html/order_invoice.tpl" order=$orders_data[oi].order customer=$orders_data[oi].customer products=$orders_data[oi].products giftcerts=$orders_data[oi].giftcerts}
{if not %oi.last%}
{$separator}
{/if}
{/section}
</html>
this should give you a starting point. Note, I have HTML mail enabled.