The most immediate difference is the fabric density. While standard sets may hover around 300-400 thread count, typically start at a minimum of 600 thread count, often reaching 800 or 1000.
The word "Sets" in the product name is not decorative. Many manufacturers produce high-quality individual components. WALS produces matched sets . When you order a Roberta Extra Quality set—say, a valve spool and its corresponding sleeve, or a piston and cylinder bore—you are not receiving two individually precise parts. You are receiving two parts that were machined sequentially on the same lathe, using the same tooling setup, measured with the same laser interferometer, and then validated together on an air-gauging test stand. wals roberta sets extra quality