Didn't find anything wrong with this mod but, I did want to add some suggestions based on what we needed on one customer's packing slip.

There needed to be explicit guarantee and care instructions that needed to be on one page. There was no way that the information would print all on the one page and we didn't want it to wrap.

The solution was to send all the text to the next page if would not fit on the first.

We first added a <div id=packSlip> to the beginning of the text and (of course) </div> at the end.

In the YOUR_ADMIN/includes/stylesheet.css we added a #packSlip call of #packSlip{page-break-inside: avoid:}.
This keeps the information inside the #padkSlip on the same page.
Not needed but what we added since all packing slips will move this to our second page, was
HTML Code:
<hr><h3 style="">***SEE REVERSE ***</h3>
This gives a nice separator after the last item on the packing list and reminds the customer to look on the other side. If your particular case would only use this if you had more than X items on a packing slip, you will need to create an if for that.

Our final look was something like
HTML Code:
<hr />
<h3 style="text-align:center"><b>*** SEE REVERSE ***</b></h3>
<div id="packslip">
<p>Information About the Guarantee Went HERE</p>
    <li>Information About Jewelry Care Went HERE.</li>
Hope this helps someone out there.