Q&A for How to Make a Roman Style Shield

You can use a plate in the cardboard shield. Place the plate in the border of the shield, copy the curve with pencil/pen, then repeat on all the sides. When you are finished copying, cut by the lines.

Try using a saw on the edges and making a gentle curve. If that doesn't work, try breaking off the end and sanding the jagged edge.

Designs varied, but typically incorporated animal elements like eagles, lions, and griffins, or linear formations that including straight lines, jagged edges and arrows. Occasionally, the area around the outside of the shield would be lined in a pattern resembling a garland of leaves.

Yes, you can. It wouldn't be as strong as the wood shield, but it can still be used for cosplay and will look pretty good if done right.

If you want it to be metal, you can go to any pet store and get a dog bowl your hand fits into. Then start to hammer the inside of the bowl, rounding it out.

Yes, you can, although the materials might be difficult to come by.

Roman shields were called "Scutum" by the Romans. If you take a look at the Wikipedia page for Scutum one of the images is of a shield found during an excavation in a place called "Dura Europos". If you can't find the image, the shield is mostly red with a circle in the middle and squares coming out from it. The one pictured seems to have been designed with lions and eagles too.