Formatting a gift certificate

I am selling a gift certificates online and on purchase of the certificate, it sends out a custom invoice to the customer. The format of the print out is almost like a paper gift certificate, see attachment. The highlighted blue columns are part of a table, nest within table with dotted border.

I am wondering if I can output the same format in a pdf using this module! I tried modify the included views (invoice_line & pdf_invoice). I am able to position the different elements using X & Y coordinates but not sure how do I add the border to the view customfield or to the entire page. It may be my lack of understanding of tcpdf apis on how to change the rendering it using $this. Can somebody give me few examples/tips on how to format this better? Thanks