Unless plastic boats are specifically required for your application, consider the LevGo smartBoats line of Paper Weighing Dishes.
LevGo smartBoats are easier to handle than weighing paper and are a simple way to reduce plastic use in the lab. Made of grease proof FSC(R) Mix Paper designed for food contact: 21 CFR 176.170 “components of paper in contact with aqueous and fatty foods” and 2I CFR 176.180 - “components of paper in contact with dry foods”. Compatible with heat applications with a temperature limitation of 2I0C. The LevGo smartBoats are available in both brown for light colored samples and white for dark samples.
LevGo is Forest Stewardship Council Chain of Custody Certified (SCS-COC-003998-BO), which assures that from Forest to Paper Mill to LevGo to Lab - the paper product you receive meets the stringent requirements of Forest Stewardship Council.