More Textures
Cross Stripes@2X #48
 Dark  CC BY-SA 3.0

Nice and simple crossed lines in dark gray tones.

Source Stefan Aleksić

Always Grey@2X #54
 Dark  CC BY-SA 3.0

Crossing lines with a subtle emboss effect on a dark background.

Source Stefan Aleksić

Elastoplast@2X #283
 Light  CC BY-SA 3.0

A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.

Source Josh Green

Prismatic 3D Isometric Tessellation Pattern 6 #148
 Dark  CC 0

Prismatic 3D Isometric Tessellation Pattern 6

Source GDJ

Background pattern 333 (version 2) #1739
 Blue  CC 0

The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i

Source Firkin

Checkered Pattern@2X #323
 Grid  CC BY-SA 3.0

Simple gray checkered lines, in light tones.

Source Radosław Rzepecki

MBossed #193
 Grid  CC BY-SA 3.0

Embossed lines and squares with subtle highlights.

Source Alex Parker

Fabric pattern (colour 2) #2401
 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

Background pattern 272 #2057
 Brown  CC 0

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

Source Firkin

Green Fibers #91
 Dark  CC BY-SA 3.0

The green fibers pattern will work very well in grayscale as well.

Source Matteo Di Capua

Black Scales #191
 Dark  CC BY-SA 3.0

Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.

Source Alex Parker