Little Knobs@2X #311
 Light  CC BY-SA 3.0

White little knobs, coming in at 10x10px. Sweet!

Source Amos

 More Textures
Background pattern 235 #2255
 Yellow  CC 0

To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Dark Blue Gray Wallpaper Texture #901
 Stripes  CC BY-SA 3.0

This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!

Source V. Hartikainen

Prismatic Rounded Squares Grid 4 No Background@2X #492
 Noise  CC 0

Prismatic Rounded Squares Grid 4 No Background

Source GDJ

Background pattern 41 #262
 Fabric  CC 0

A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.

Source Firkin

Dark Brick Wall #135
 Wall  CC BY-SA 3.0

Black brick wall pattern. Brick your site up!

Source Alex Parker

Prismatic Groovy Concentric Background 3 #457
 Noise  CC 0

Prismatic Groovy Concentric Background 3

Source GDJ

Seamless 3D Isometric Tessellation Pattern 2 #147
 Light  CC 0

A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).

Source GDJ

Fabric pattern 3 (colour 5) #2383
 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

Tessellation 16 (colour 5) #2211
 Yellow  CC 0

The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.

Source Firkin