More Textures
Green Fibers@2X #92
 Dark  CC BY-SA 3.0

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

Source Matteo Di Capua

Sine wave background 2 #1734
 Dark  CC 0

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

Source Firkin

Fake Brick #358
 Dark  CC BY-SA 3.0

Black, simple, elegant, and useful.

Source Marat

Retro Circles Background 7 No Black@2X #434
 Unknow  CC 0

Retro Circles Background 7 No Black

Source GDJ

Background pattern 226 (colour 5) #2317
 Blue  CC 0

A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Little Knobs #310
 Light  CC BY-SA 3.0

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

Source Amos