If you want to make 3D glasses from poster board, you first have to download the standard size of the glasses. In order to do that you must visit the following link:
Once you visit this link, you will notice that there will be a template for the glasses which is also the standard size.
Print the file which is available on the source provided in the first step. First trace the whole shape on to a regular piece of paper and then use the cutting to trace the shape on a posted board. Make sure that you perfectly cut the holes for your eyes.
Now, with the glasses cut, you need the blue and red colored papers which will fit the holes which you have cut for your eyes. A plastic wrap is the type of material that you will need since you also have to look through the glasses. In case you are using a normal plastic wrap, you will have to color one blue and the other one as red. However, it is advised that you use acetate paper of both these colors.
With the ‘lens’ for both your eyes cut out, now you have to fix them on the glasses. While some suggest that glue is a better option, it becomes difficult for you to stick the paper on to the poster board. Therefore, use tape to connect the plastic wrap or acetate paper to your glasses. Once the lenses have been connected, tape the sides of your glasses together in order to give them the perfect shape. Try putting the glasses on in order to check whether they are of the perfect shape and size or not.
Some people give these glasses a better look by not using the poster board. Instead, they would purchase cheap sunglasses, remove the lenses by popping them out and then use either plastic wraps or acetate paper to fill the holes. This way the glasses made are not fragile.