Whirl-Pak® Write-On Bags are sterile, single-use sampling bags designed for secure collection, transport, and storage of liquid or solid samples where clear, reliable sample identification is required.

Constructed from high-clarity virgin polyethylene film, these bags provide excellent visibility of contents while maintaining strength and puncture resistance. A continuous perimeter seal ensures leakproof performance, and reinforced wire closure tabs allow fast, reliable sealing by folding and twisting the bag closure.

The integrated white write-on strip features a paper-like surface that accepts ballpoint pen, pencil, or felt-tip marker with minimal smearing, enabling clear labeling and traceability directly on the bag. Each bag is sterilized after manufacturing to preserve sample integrity and is suitable for freezing applications, including ultra-low temperatures, when handled carefully after freezing.

This 118 mL (4 oz) Whirl-Pak® Write-On Bag is ideal for small-volume microbiological, environmental, food safety, and water testing applications requiring clear sample identification.