Signwarehouse.com estimates that on average 40% of a sign shop’s income is from custom-made banners. Priced correctly, they can be a substantial bottom-line contributor.
The market is apparently large and includes high volume sales to retail stores or lower volume sales to institutions such as schools, municipalities, and corporations.
The key of course is to have the appropriate equipment and materials and then learning to install banners properly. You probably have the equipment so perhaps all you have to do is research the other requirements.
And finally, appropriate pricing is important. Apparently banners can yield higher margin percentages than other sign products. Local market conditions will have to be researched to ensure that you neither leave money on the table nor price yourself out of the market.
Maybe 2020 can be your year of banner sales!