What technique involves squeezing the upper part of a thrown form on the wheel?

The correct answer, collaring, refers specifically to the technique of gently squeezing the upper part of a thrown form while it is on the potter's wheel. This method allows the potter to refine the shape and control the height of the vessel. By applying pressure to the upper section, the potter can create a more defined neck or lip, resulting in a smooth and elegant form. Collar techniques are often used to streamline and add finesse to the profile of vessels, making them visually appealing and functional.

In contrast to collaring, the other techniques involve different approaches to shaping clay. Smooshing does not specifically denote a recognized pottery technique, and could imply a less precise manipulation. Pinching involves using the fingers to pinch and shape the clay into forms, mainly when starting from a solid mass rather than on the wheel, and coiling consists of building up walls by adding rolled pieces of clay, which is a distinct method of construction that does not involve the wheel in the same way as collaring.