| 摘要 |
<p>PURPOSE:To provide a chalk solution capable of writing characters by making the most of writing brush characteristics or drawing paintings by a paint brush directly on a blackboard, glass, wood, plastic, metal corrugated board, etc., being quick drying and capable of easily wiped out by a blackboard wiper, etc. CONSTITUTION:The solution is obtained by dissolving calcium carbonate or burnt gypsum powders in a highly volatile liquid.</p> |
