Trails are the in-game items in Bowling Crew that are used for customizing balls and appear as a trace mark following the ball. Any ball can be customized with the trail.
How to decorate balls with trails?
Choose the ball you would like to decorate in the Arsenal screen by tapping its card.
In the pop-up window tap the Customization tab, then choose Trails.
Click on the trail you would like to use to preview how it will look with your ball. Once you've chosen a trail, tap Set Trail.
How to gain trails?
3 types of trails are available on default: blue, violet, and green. You can apply them on your balls the way you like!
Most of other trails are premium. They are available limited time only. But you can get this cool one by winning Friendly Matches.
New trails will become available with game updates. Stay tuned!