Paint and Chalk Scourability Studies

In order to track and record information on individual animals, paint and chalk branding is a necessity for many sheep producers across the United States, although wool processors say it is best to use no paint or chalk at all. The wool processing segment of the industry has, for many years, expressed concern about the amount of paint, and some chalk, which remains in the wool after it has been scoured, costing the wool industry millions of dollars.

Most brands of paint on the market are advertised as scourable, however, there are instances when all the paint does not scour out and the remaining residue continues to be a problem.

The American Wool Council (AWC), in response to an appeal from buyers and processors, will be conducting an informational study this spring to test various paints and paint colors to see which scour out best. If the paints are indeed scourable, then it may be that, in some cases, the directions on the can are not being followed. Growers would then be reminded to adhere to all directions and to not add anything to the paint, avoid direct heat and freezing and keep the width of the paint brand to a minimum.

The study will endeavor to determine if the paint scours out of the wool and the effect the following factors have in the amount of paint residue left in the wool after scouring: the brand of the paint; the amount of paint applied to the wool; the color of the paint; and the width of the paint brand.

The wool samples will be sent to a scouring facility as well as to a lab testing facility to analyze the results. As information becomes available, the AWC will continue to update all segments of the industry on its findings.

"AWC is working to have preliminary results available for producers to use this season with the remainder of the test being completed by the end of the year. I think the results will be valuable for producers to decide which paint, if any, works best on their operation," commented Ron Cole, American Sheep Industry Association wool education consultant.

Where producers use paint as a longer-term marking tool, chalk is used to identify sheep for shorter periods. Chalk residue in the wool after scouring can also sometimes still be troublesome. In 2008, the AWC carried out an informal analysis of some of the various chalk and spray products on the market, as well as wax-based products, to determine the most effective form of marking with the least amount of residue.

The results showed that Dixon Ticondaroga chalk, pink and purple, was the only product tested that was 100-percent scourable. Richey SprayLine, orange and green, left some light residue on the wool after scouring.

All of the wax based products used in the study left significant residue following the scouring of the wool. Rota Stik, MarKing Spray, All Weather Paint Stick and LA-CO Twist Stick were the products tested in this study.

"No matter what product a producer chooses to use, it is always important to read and follow the labeling directions on the product and to know that the markings will scour out of the wool when desired," concluded Cole.