Colourful background #2007
Colorful CC 0Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
More Textures
Diagonal Striped Brick@2X #680
Stripes CC BY-SA 3.0Might not be super subtle, but quite original in its form.
Source Alex Smith
Rocky Wall #41
Wall CC BY-SA 3.0High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Diamond pattern (colour 8) #2273
Red CC 0From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Background pattern 21 #205
Light CC 0A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Merely Cubed #589
Grid CC BY-SA 3.0Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Notebook #1178
Gray CC BY-SA 3.0This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Prismatic Polka Dots Mark II No Background #530
Noise CC 0Prismatic Polka Dots Mark II No Background
Source GDJ
overlay crack #153
Noise CC 0This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Floral background 21 (colour) #1784
Dark CC 0From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Light Striped Background #937
Stripes CC BY-SA 3.0A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Flourish 3 #2298
Dark CC 0From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin