Some kind of liar

Please settle an argument with your insights.
Which one is it...
a bald face(d) liar or a bold face(d) liar?
What is the origin?
Thanks! SR

It's bald-faced. A bald-faced liar tells a bald-faced lie. I realise that this is at first glance the less logical of the two alternatives you offer, but it is indeed the correct one. Bald-faced means blatant, undisguised - so not concealed in any way.