White Block 4 mil

Reclosable White Block Bags 4 mil are our heaviest write-on zip-lock bags — built for demanding industrial applications where both extreme durability and clear content identification are required. The 4 mil gauge delivers exceptional puncture resistance and tear strength, making these bags the right choice for packaging heavy components, sharp metal parts, abrasive materials, and anything that would quickly compromise lighter-gauge bags.

The white write-on block printed on each bag provides a dedicated space for marking part numbers, quantities, lot codes, or other identifiers with a permanent marker, grease pencil, or printed label — keeping parts organized and traceable on the floor, in storage bins, or during transit. The resealable zip-lock closure secures contents between uses while allowing repeated, easy access.

Industries that rely on 4 mil white block bags include metal fabrication, automotive aftermarket distribution, MRO supply operations, industrial distribution, and electrical component packaging. If your parts are heavy, sharp, or high-value enough that you can’t afford bag failure, 4 mil is the right gauge. Available in multiple sizes to suit a range of part dimensions.