I made a video a few years ago, detailing how I made a contractor’s sandwich board sign and here is the link to that video if you are interested: https://youtu.be/2ZBK4nP-39E
This video is how to make a “quick & dirty” sandwich board sign on the cheap and maybe for free if you have sufficient scrap materials sitting around. For those interested, these sandwich boards were made with ½” thick A/C exterior plywood, measuring 2’ x 3’ for each sign. The solid wood I used for making the hinges was 1×4 pine, 2’ long and the reason for adding that instead of simply lashing the plywood itself, is because the plywood is very splintery and rough. It would rapidly cut through the rope I used in very little time, where the solid pine can be sanded very smooth – plus I already had the wood in my shop so why not use it? The line or rope I used was 3/16” pull cord (for chainsaws and other small engines) and I chose to use it because I have a whole spool of it.
I made a pair of these as a volunteer for “Women for Healthy Rural Living” (WHRL), a local non-profit organization. They will paint these sandwich board signs with three coats of blackboard chalk paint and they will be used at the local Milbridge Health and Wellness Park (also built by WHRL) in the Incredible Edible Milbridge gardens (free veggie gardens available to the public by WHRL). The signs may change daily, letting people know what is ripe and ready to pick. Check out WHRL’s website: https://www.whrl.org
Here’s the video: