Amazon has 2-Pack IRWIN Tools STRAIT-LINE Lumber Crayons on sale for $1.29 . Shipping is free with Prime or on order $25+
- For use on oily, slick, wet, cold, or dry surfaces.
- Ideal for marking lumber, concrete, ceramics, rubber, metal, paper, and cardboard.
- Wax-based crayons are non-toxic and waterproof.
- Marks are weather-resistant.
Amazon offers free shipping with $25+ orders or get free 1 day shipping on all orders with a free trial of Amazon Prime. A prime trial is also free with Amazon Family (which also gets you up to 20% off diapers among other benefits) or Amazon Student. EBT/Medicaid Cardholders can save on Prime Membership here.