other optional ingredients may include but are not limited to humectants and biocides a humectant is an ingredient that can retain water and includes liquids such as poly glycols and ethoxylated glycerol and solids such as urea biocides prevent microbial degradation u2014 their selection and use is generally well known in the art in a preferred embodiment the pretreatment solution comprises urea preferably in an amount ranging from about 0 5 wt to about 5 wt based on the total weight of the pretreatment solution the ingredient levels must be sufficient to provide adequate coating weight after drying but not so high that the solution becomes too viscous and fails to coat and penetrate the fabric evenly the viscosity at 25 u00b0 c is preferably greater than about 100 cp and less than about 2000 cp more preferably between about 200 and about 1000 cp and especially between about 250 and about 500 cp the ph of the pretreatment solution is preferably between about 6 and about 8 and preferably about neutral the fabric to be pretreated is preferably a woven fabric comprising synthetic polyamide fibers most commonly the synthetic polyamide fibers are nylon 6 and or nylon 6 6 fibers for flag and banner stock the fabric is generally about 70 to about 200 deniers a.