Background pattern 306 (colour 4) #1877
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

 More Textures
Prismatic Rounded Squares Grid 3 No Background #489
 Noise  CC 0

Prismatic Rounded Squares Grid 3 No Background

Source GDJ

Background pattern 302 (colour 2) #1893
 Dark  CC 0

The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.

Source Firkin

Diamond pattern (colour 5) #2281
 Red  CC 0

From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Prismatic Isometric Cube Wireframe Pattern No Background@2X #500
 Light  CC 0

Prismatic Isometric Cube Wireframe Pattern No Background

Source GDJ

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 Grunge Background #1124
 Grunge  CC BY-SA 3.0

This white background pattern has a seamless grunge style texture. Here's a white grunge style background pattern. Use it as a tiled background image on web sites or for other purposes.

Source V. Hartikainen

Background pattern brown #1951
 Brown  CC 0

To get the tile this is based on, 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

Prismatic Polka Dots Mark II 2 No Background #532
 Noise  CC 0

Prismatic Polka Dots Mark II 2 No Background

Source GDJ

Soft Kill #318
 Dark  CC BY-SA 3.0

Pattern #100! A black classic knit-looking pattern.

Source Factorio.us Collective

Background pattern 8 (black) #209
 Dark  CC 0

Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net

Source Firkin