If you sell on eBay, you may have noticed a very annoying eBay / Chrome bug that started to appear in the past few months when trying to print an invoice or packing slip. This is due to a spacer image that eBay uses that is not supposed to be visible in browsers but it is for some reason in Chrome.
If you contact eBay seller support about this issue, they will almost certainly recommend that you switch to a different browser (hardly a perfect solution, since other browsers have different problems with eBay).
After digging into a code a bit, I found the culprit image and wrote a bookmarklet that lets you, with a single click, get rid of the dreaded gray vertical line, so that you can print the packing slip / invoice the way you intended.
To use the bookmarklet, simply drag and drop the blue button below to your Chrome bookmark bar, go to the eBay invoice preview you are about to print (the one with a line), and click on the bookmarklet. The line should disappear allowing you to print clean looking eBay invoices.
EDIT: It seems that eBay has added an Onload Print function. Before you are able to click the bookmarklet, dismiss the print window, either with Cancel button or by hitting Esc on your keyboard. When you are back to the invoice page, click the bookmarklet in the bookmarks bar to apply the fix, and Ctrl+P or Menu > Print to print the invoices.
Feel free to post suggestions or comments if this is not working or stops working for you (if eBay updates) and I will try to revise the code.
EDIT (May 5th 2016): Thanks to many of my readers who commented with instances where this bookmarklet did not work. Latest change now includes a fix to remove line on “Address labels and invoice/packing slip” page as well. Please delete your old bookmarklet and use the updated one above (blue button).