I brought the sketch panels down to the bottom of the card. Made my card base 4 1/4 by 3 3/4 and overlapped the edge by 1/4" on both sides with my banner making a square card that fits in an A2 envelope.
Paper: Vellum Cardstock, Recollections 110# White (Michaels), Crafters Companion Ultra Smooth Premium White Cardstock, Classic Kraft, True Black (Papertrey Ink), Plus One (Amy Tangerine)