A mate who owns a kite shop had some done some years ago for flying at festivals, i helped out with the design that went on it. Look great flapping about in the wind!
Just think you need to remember because of the lightweight material (ripstop nylon of sorts) used that they are fairly transparent once up so the logo will read correct from one side and reversed on the other. Depending on what you want on it exactly you may want to arrange a design to compensate so it can read correct when viewed from either side, even if it's just partially. Large logo's look good either way. It's just small bulk blocks of text that needs thinking about more.
A plain white background is the cheapest option,and the retrobike logo would work well on plain white
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Just normal vinyl banners look rather cheap,£4 off each Mcretro member and we've have our own