Background pattern 215 (colour 3) #2369
Pink CC 0A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
More Textures
Use Your Illusion@2X #918
Dark CC BY-SA 3.0A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
White tiles@2X #728
Grid CC BY-SA 3.0A nice and simple white rotated tile pattern.
Source Another One
Green Background Pattern with Warped Vertical Stripes #1328
Green CC BY-SA 3.0Green Background Pattern
Source V. Hartikainen
Background pattern 18 #202
Dark CC 0A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Rocky Wall@2X #42
Light CC BY-SA 3.0High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Padded@2X #62
Dark CC BY-SA 3.0A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Decorative divider 216 #2243
Dark CC 0Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black #402
Noise CC 0Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Floral design 94 #1792
Yellow CC 0From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin