Your yard signs need to be able to accommodate different images front and back.
Here’s my issue – I need signs to point in a particular direction, in my case, towards a car show, but it could be a garage sale, open house, etc. The signs will have an arrow pointing in one direction, say Left.
Visualize the car show West of the sign.
If both sides have the same image, the people looking at the front of the sign will see the arrow point to the Left, which is West, while others looking at the back of the sign will see it pointing to their Left, which is East.
In order for the people looking at the back of the sign to also be directed West, the back of the sign would have to point to the Right. This way, both sides of the sign would be pointing in the same direction.
This setup also allows you to turn the sign 180 degrees and have the front point Right (East), and the back would be pointing Left (also East). The arrows on each side are essentially mirror images (note that the rest of the sign cannot be an exact mirror image as the text on one side would not be legible).
Look at the two images I’ve uploaded to see an example of what is needed.