A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Prismatic Groovy Concentric Background No Black
Source GDJ
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Sharp pixel pattern, just like the good old days.
Source Paridhi
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
One more sharp little tile for you. Subtle circles this time.
Source Blunia