USG No. 1 Moulding Plaster is the economical general-purpose choice for mold making, waste molds, temporary patterns, sculpting and traditional plaster casting. Often described as a professional plaster of Paris, its fine grain reproduces detail well when extreme hardness or dimensional performance is not required. Choose this grade for general plaster work; move to Hydrocal White or Hydro-Stone when the finished casting needs substantially greater strength and hardness. Browse the full USG Plaster & Gypsum Cement collection.

Often referred to as plaster of Paris or soft plaster, No. 1 Moulding Plaster is used to create waste molds or temporary patterns where surface hardness and strength are not crucial. No. 1 Moulding Plaster:

• Offers a controlled set that provides uniform workability
• Has a fine grain – making it ideal for producing sharp detail when used neat for cast work
• Complies with ASTM C28
• Sets in 27-37 minutes after mixing
• Requires 70 parts water by weight per 100 parts plaster
• Is available in 50- and 100-pound bags