A dark wool background pattern with diagonal stripes #907
 Stripes  CC BY-SA 3.0

Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.

Source V. Hartikainen

 More Textures
Flowery pattern 4 #2328
 Colorful  CC 0

Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Prismatic Curved Diamond Pattern 7 No Background@2X #548
 Noise  CC 0

Prismatic Curved Diamond Pattern 7 No Background

Source GDJ

Retro Squares Background 9 #399
 Dark  CC 0

Retro Squares Background 9

Source GDJ

Prismatic Dots Background 6@2X #512
 Dark  CC 0

Prismatic Dots Background 6

Source GDJ

Background pattern 227 (colour 3) #2312
 Pink  CC 0

A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.

Source Firkin

Background Patterns - Emerald #252
 Fabric  CC 0

If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117

Source Viscious-Speed

45-Degree Fabric@2X #2
 Fabric  CC BY-SA 3.0

Medium gray fabric pattern with 45-degree lines going across.

Source Atle Mo

Pinstripe@2X #36
 Light  CC BY-SA 3.0

Light gray pattern with a thin pinstripe.

Source Brandon

Background pattern 3 #222
 Noise  CC 0

A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.

Source Firkin

Felt@2X #301
 Wall  CC BY-SA 3.0

Got some felt in my mailbox today, so I scanned it for you to use.

Source Atle Mo

Subtle Orange Emboss #97
 Light  CC BY-SA 3.0

A hint of orange color, and some crossed and embossed lines.

Source Adam Anlauf