Here is a vector of abstract waves background form thevectorart.com, scalable Illustrator format. This means they’re fully scalable, available to use for print or any other digital medium.

Name: Abstract Waves Vector Background
Homepage: vector
License: Creative Commons Attribution 3.0
File Type: EPS
This image is a scalable vector graphic and can be scaled to any size without loss of resolution. This image will download as a .eps or ai file. You will need a vector editor to use this file (such as Adobe Illustrator or CorelDRAW).