Yes, a kneadable eraser can harden over time if it is exposed to air or if it is not stored properly. Kneadable erasers are made of a pliable material that can become firmer as it dries out. To prevent hardening, it is important to keep the eraser in a sealed container or wrap it in plastic when not in use. If a kneadable eraser does harden, it may still be usable after kneading and warming it up in your hands to soften it again. **

Your dough will be kneadable once the ingredients are fully combined and you have achieved a shaggy mass. At this point, you can start kneading the dough to develop the gluten and create a smooth and elastic texture. Depending on the recipe, this may take anywhere from 5-10 minutes of kneading. It's important to follow the recipe instructions and trust the feel of the dough to determine when it is ready to be kneaded. **

Yes, a kneadable eraser can become hard over time if it is exposed to air for an extended period. The eraser material can dry out and lose its pliability, making it difficult to knead and erase effectively. To prevent this, it is recommended to store kneadable erasers in a sealed container or plastic bag when not in use to help retain their softness and flexibility. **

To store a kneadable eraser, it's best to keep it in a cool, dry place away from direct sunlight and extreme temperatures. You can store it in a plastic container or a resealable bag to protect it from dust and dirt. Make sure to keep it away from any oily or greasy substances, as these can affect the eraser's performance. Proper storage will help keep the eraser soft and pliable for longer use. **