There are some great graphics on these recycled billboard banner Macbook sleeves. My favorites are below, but there are a bunch more to choose from. All sleeves are padded with 6mm/0.25-inch of PE foam on each side and come with a velcro closure.
Shown above: 13″ Macbook Sleeve No. 64
MacBook Pro Sleeve 13 inch No. 57
MacBook Pro Sleeve 13 inch No. 43
Available from NottyPooch on Etsy, 64.00.
MacBook Pro Sleeve 13 inch No. 63