All our mason line is
Construction Line / Mason Line
This 100% nylon line is ideal for laying out foundations, level line for laying brick, and many other construction uses. Don't confuse this line with the "synthetic" line that most hardware stores now sell. This 100% nylon line has the proper stretch, strength, and abrasion resistance that professional carpenters need.
The bottom 4 items with "/Blk" in color have a black tracer in the line. These 4 items are also bonded.