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

 More Textures
Background pattern 209 #2432
 Grid  CC 0

A seamless pattern with polka dots.

Source Firkin

[email protected] #1108
 Light  CC BY-SA 3.0

A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.

Source Dima Shiper

Prismatic Geometric Tessellation Pattern No Background #551
 Noise  CC 0

Prismatic Geometric Tessellation Pattern No Background

Source GDJ

Mooning #1140
 Gray  CC BY-SA 3.0

The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?

Source Joel Klein

Banner pack 6 #2438
 Colorful  CC 0

Three coloured banners. From an image on Pixabay.

Source Firkin

Background pattern 21 #205
 Light  CC 0

A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.

Source Firkin

stone filter pack #154
 Stone  CC 0

This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.

Source Lazur URH

White Bed [email protected] #822
 Light  CC BY-SA 3.0

Nothing like a clean set of bed sheets, huh?

Source Badhon Ebrahim

Star pattern #2410
 Brown  CC 0

A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Water & Yellow #1575
 Yellow  CC 0

Incoming catena. Water & well. CC0 texture.

Source Unknow

Metal & Gray Stone #1656
 Metal  CC 0

Metal-Rusty. CC0 License.

Source Unknow

Halftone #1310
 Light  CC BY-SA 3.0

Halftone, not halfling. Got it?

Source Atle Mo

HIXS Evolution #609
 Dark  CC BY-SA 3.0

Heavy depth and shadows here, but might work well on some mobile apps.

Source Damian Rivas

"Polished Stone", Gray Background Pattern #1053
 Stone  CC BY-SA 3.0

A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).

Source V. Hartikainen

Knitted Netting #603
 Grid  CC BY-SA 3.0

A bit like some carbon, or knitted netting if you will.

Source Anna Litvinuk

Dark Denim #29
 Dark  CC BY-SA 3.0

A dark denim looking pattern. 145×145 pixels.

Source Atle Mo

Floors & Dark #1617
 Wall  CC 0

Floors-Tiles. CC0 License.

Source Unknow

Zig Zag #328
 Dark  CC BY-SA 3.0

So tiny, just 7 by 7 pixels – but still so sexy. Ah yes.

Source Dmitriy Prodchenko

Subtle Orange [email protected] #98
 Light  CC BY-SA 3.0

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

Source Adam Anlauf

Background pattern 315 (colour 6) #1840
 Green  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 220 #2360
 Dark  CC 0

A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.

Source Firkin

Mocha [email protected] #1100
 Gray  CC BY-SA 3.0

You don’t see many mid-tone patterns here, but this one is nice.

Source Joel Klein

Fleurs-de-lys pattern 2 (colour) #2204
 Colorful  CC 0

Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.

Source Firkin

Prismatic Abstract Geometric Background 5 #401
 Noise  CC 0

Prismatic Abstract Geometric Background 5

Source GDJ

Cross pattern (negative) #2332
 Dark  CC 0

A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.

Source Firkin