There's various levels of what we consider "vintage" Halloween masks. Many children of the 70s (peak of Halloween mania), were the first ones to enjoy manufactured masks and costumes all pre-made, though thankfully creative kids and moms still made their own!
Another popular mask for Halloween in the 60s and 70s was cardboard ones offered on cereal boxes and other items that you could cut out and attach a string and wear. Their flat look and simple designs were actually kind of freaky.
Then, there's the creepy-ass vintage homemade ones -
Curious to try your own mask making for something vintage and homemade? Start with a basic craft mask - $6.99 or you can get one in any craft store.
A little bit of paper maiche, plaster of paris or even Latex, and you're good to go!
Some great tricks to think about are things like using crackling medium. They sell it with acrylic craft paints. It's a clear gel, so you can put down a color on the mask, put the gel on, let it dry, then paint another color over it and it cracks that surface to show what is underneath. If you want something to look super old, get a black glaze and rub it onto the mask, and rub it off, leaving the black to stain it slightly off and to get into the cracks and make them black.
The first method I used on this plague mask -
The second technique, I used on this mannequin head to age it -
Don't be afraid to try things like putting a dab of paint in a bunch of water and using it to make a wash that yellows the mask, use yellow ochre or even a raw umber brown.
I say do a homemade mask - there really is nothing more frightening than the vague, backwoods, almost primitive look -