UV resistance is perhaps the most important consideration when evaluating an outdoor fabric. A rating of 3 or better is excellent. Highly UV resistant fabrics will last longer when exposed to sunlight consistently. Also, a manufacture’s warranty is always a great way to judge UV resistance. Longer warranties almost always correlate to life expectancy when exposed to sun, rain, snow, wind, etc. As an estimate you can assume that the chart’s ratings also indicate useful life in years of harsh sun exposure.