Why is my ink washing off my Filter Bags after my NDF run?

When labeled with the acetone resistant marker (part # F08), F57 and F58 bags must be sprayed or wetted with acetone and allowed to air-dry prior to the analysis. 

The acetone resistant marker will wash off the bags if it is not set with acetone prior to the analysis. 

Alternatively, bags can be labeled with a stamp (part #s TN2 & TP2). This ink does not have to be set with acetone prior to a NDF analysis.