Axiom Pattern #330
 Grid  CC BY-SA 3.0

Not even 1kb, but very stylish. Gray thin lines.

Source Struck Axiom

 More Textures
Seamless Colorful Floral Pattern Background #256
 Fabric  CC 0

PDP

Source GDJ

Background pattern 223 (colour 5) #2349
 Blue  CC 0

Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Patern dots #241
 Dark  CC 0

Pattern repeating background 48x48

Source Keistutis

Retro Squares Background@2X #415
 Noise  CC 0

Retro Squares Background

Source GDJ

Fabric pattern (colour 3) #2400
 Fabric  CC 0

Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Fancy Deboss@2X #178
 Fabric  CC BY-SA 3.0

Luxury pattern, looking like it came right out of Paris.

Source Daniel Beaton

Background pattern 315 (colour 4) #1842
 Colorful  CC 0

The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Background pattern black and white #2030
 Dark  CC 0

A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.

Source Firkin

Random Binary Background #274
 Light  CC 0

Random Binary Background

Source GDJ

Seamless Background Texture (Light Pink) #1231
 Pink  CC BY-SA 3.0

Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.

Source V. Hartikainen

Background pattern 227 (colour 4) #2311
 Green  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