Square plastic containers are developed to improve shelf presentation, storage density, and pallet utilization. The straight sidewalls create a clean appearance and provide a broad surface for labels or printed graphics. Capacity, length, width, height, wall thickness, lid fit, handle style, color, and decoration can be adjusted to project requirements. Secure closures and stackable structures can be selected for different filling and transport conditions. These custom square plastic containers are suited to food, powders, chemicals, household products, and private-label packaging programs.