In 2012, the International Tennis Federation changed the “Official Rules of Tennis” to include specific rules for 10 and under competition. This was a change heard around the world facilitating the addition of blended lines to tennis courts. Many national sports bodies responsible for tennis such as the USTA and Tennis Canada provided grants to help facilities comply with the new rules.
In the United States 2,709 courts for 10 and Under Tennis (36’ and 60’) were built or lined in 2014.
The following link by Tennis Canada shows some Canadian clubs taking advantage of the grants.
If you are vacationing note whether the courts you are using have blended line. Many players do not even notice them.