modeling clay non hardening

Oven‑bake (polymer) clays are hardened by baking in a home oven. Typical instructions list 275 °F (130 °C) for about 15 minutes per 1/4 in (6 mm) of thickness.

For lightweight air‑dry clays, keep them sealed in an airtight container or resealable bag to preserve softness. Uncured oven‑bake (polymer) clay should be stored in a cool, dry place out of direct sunlight (around or below 77 °F), preferably in polypropylene containers or bags.

These clays are used for jewelry making, small figurines, DIY home décor and mixed‑media projects. Lightweight air‑dry materials are also promoted for ornaments, keepsakes, slime ingredients and general kids' crafts.

Two main types fit that description: oven‑bake (polymer) clays, which remain soft until baked in a home oven, and lightweight air‑dry modeling materials, which can be air‑dried to set or kept soft for reuse by sealing them in an airtight container.

Air‑dry modeling materials are typically lightweight, flexible when dry, non‑crumbling and not sticky to hands. Many are labeled non‑toxic and reusable; they can be air‑dried to make solid creations or stored airtight to remain soft for future use.

Labeling varies by product. Some packs are labeled "Suggested Age: 3 years and up" while others show "Suggested Age: 8 years and up," so check the specific product label for age recommendations.

Common package weights shown include 2.25 oz, 2.5 oz, 4 oz, 7 oz and 8 oz bars/packs, as well as 1 lb packs.