These Stop and Go Bags, also known as stick / slick or Stop / Slide, are weather friendly and last longer. They are filled with plastic pellets, so the weight stays consistent comparing to whole corn that breaks down. They are made to regulation with 6" x 6" dimensions, scaled to weigh 16 oz, rounded corners. I have a lot of these bags that are not pictured.
ChicaliBoards.com
$40-$55 for a set 8 bags, depending on fabric. Some of this bags are very slick and slide in any condition. Other bags are not as slick for better control.