Before there were fancy bases, there was the cup. One square, four folds, and suddenly you have something with a bottom, two walls, and an opening wide enough to hold a handful of peanuts. It is the model people learn by accident and then use for the rest of their lives.

Fold it from a scrap of paper at a picnic table and you have a temporary dish; fold it from thicker paper and it becomes a desk tidy. Either way, it takes under a minute.

This little paper cup is one of the oldest tricks in folding: a square becomes a vessel in four moves, with no glue and no cutting. It holds snacks, paperclips, or a few folded stars, and it collapses flat again when you are done with it.

Work with crisp paper and press every crease sharply, because the cup only holds its shape when the side walls are creased hard. A 15 cm square makes a cup roughly the size of a shot glass; scale the paper up for something bigger.

Step 1.

Fold the square in half.

Step 2.

Fold the top layer over at the position shown in the photo.

Step 3.

Fold the flap down at the position shown in the photo.

Step 4.

Repeat the same fold on the back side.

Completion.

Open the cup out and adjust the sides, and your paper cup is ready.