I just bought a book by Zoe Clark. In it she has a vertical line spacer to emboss vertical lines on a cake. (Tuxedo Cake) Does anyone know where I could buy this? I've googled it with no luck.

I know I could make stripes with fondant/gumpaste, but I like the embossed look.
Thank you in advance for any help!

Run to the stationery store or hardware and grab a set square.Try that.

Jem , has them they are called strip cutters.

http://www.globalsugarart.com/cat.php?cid=647&s=16&name=Gumpaste%20Cutters/Bows,%20Ribbons%20&%20Strips

Link to strip cutters