Abstract: A container made of plastic material and useful for holding paint or other substances has a cylindrical wall formed, around its upper end, with an inwardly projecting flange molded in one piece with the wall. Releasably interengageable formations on the flange and a peripheral portion of a lid secure the lid. A container bottom is formed separately from the wall and is bonded to the lower end of the wall to facilitate molding of the wall and the flange. The interengageable formations comprise annular projections on the lid and the flange and wedge formations on the lid and the flange urge the annular projection on the lid radially outwardly into engagement with that on the flange, the annular projections providing a primary lock between the lid and the flange which must be pried open before a secondary lock can be released.