i used a 24 inch pepakura file, the lightweight fiberglass is good for walking around at cons. other options are stripping the paint off a Flexible Flyer steel sled, only $30 on amazon. on a side note, titanium is 2x harder than steel, so itd be harder to work with, plus its not 'silver' like steel is, its more of a 'tan steel' color so your color will already be off.
more notes,the screen used size is 25" with a 3" bow, verified in the profiles in history auction. and yes the comic is 30" with a 5" bow.