A spout, especially suitable for a heavy duty liquid detergent container fitment, is made by thermoforming. Preferably the spout is part of a fitment which includes a bottom wall extending from the bottom of the spout wall, a circumscribing wall surrounding the spout and extending from the bottom of the bottom wall and a peripheral radially extending flange extending from the top of the circumscribing wall. The thermoformed spout/fitment finds special use in plastic containers having inside blown threads. The inside blown threads mate with external threads on a closure.