“Necessary and Sufficient Conditions” is a series of portraits of philosophers that was given that name because, in the words of the artist, “the idea is to include as little as possible in the portrait while still making it work as a representation of the person.”

Antti Kauppinen (Helsinki) makes the portraits “using a printed photo and a sharp knife.”

Below is a sampling:

There are about 3 dozen in total. He adds:

Because they’re so minimalistic, these pictures are suitable for mugs, t-shirts, stickers, slides, or even stencils for graffiti (that’s how I destroyed my Marx before taking a proper photo…). Many of these things can be ordered from an online photo service. In my experience, they make it easy for you to print your own photo on just about anything these days. Needless to say, please don’t use the pictures without proper attribution or for financial gain—and maybe send me a picture of what you’ve done!

You can see the whole collection here.