Not a very good hobby

Pretty sure they're illegal in most places but you can make it if you really want to

I need to buy a butterknife

They're not illegal in the states

Why're they illegal?

Because they're technically a concealed weapon

And a regular folding knife?

I don't know

If it has a blade that is over 3 inches it's illegal. If it locks it's illegal whatever length it is, unless you have a "good reason" for carrying it in public

Huh. Different strokes I guess.