This shirt really resembles chainmail and it's what some films like Monty Python and the Holy Grail and the Lord of the Rings did when the costumers didn't feel like making actual chainmail.
So without further a-do, I bring you: Lazy-Man's Chainmail.
Step 1: Materials List
A knitted sweater: I Got this at the thrift store for about 2 bucks. Not just any Wool Knit Sweater would work, though. Try to look for sweaters made with big yarn and knitted to look very "Chainmail-like"
Silver Metallic Spraypaint: By now I'm sure you know where I'm going with this.
Step 2: Set Up and Spray
Spray-paint the hell out of the sweater using the Spray-paint. Leave no thread non-silver!
An easy way to do this is to hang it up in a tree or something and just spray-paint it.
If you have no way to do that just lay it on the floor or whatever and spray paint it like that. Spray-paint one side of the sweater, wait for it to dry, then flip it over and do the same. Again, leave no thread non-silver!
Step 3: Wait a Bit and Wear!
In total this cost about, 5 dollars and took about 12 minutes of actual "work" to make (It took about 3 hours before I could actually wear it, though)
It looks better if you were to wear it underneath some cardboard armour or maybe a surcoat/tabard or something.
That's it for this Instructable! Bye!