Tessellation 16 (colour 3) #2213
 Green  CC 0

The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.

Source Firkin

 More Textures
Black Paper #55
 Dark  CC BY-SA 3.0

Black paper texture, based on two different images.

Source Atle Mo
Based from Design Kindle

Abstract Tiled Background Extended 7 #518
 Dark  CC 0

Abstract Tiled Background Extended 7

Source GDJ

Prismatic Groovy Concentric Background@2X #450
 Noise  CC 0

Prismatic Groovy Concentric Background

Source GDJ

Diamond pattern (colour 7) #2274
 Red  CC 0

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

Source Firkin

Prismatic Groovy Concentric Background 3@2X #458
 Noise  CC 0

Prismatic Groovy Concentric Background 3

Source GDJ

Background pattern yellow #2025
 Yellow  CC 0

Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Robots #125
 Dark  CC BY-SA 3.0

And some more testing, this time with Seamless Studio. It’s Robots FFS!

Source Seamless Studio

Clover with background #237
 Paper  CC 0

Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.

Source BAJ

Retro Circles Background 5 #424
 Noise  CC 0

Retro Circles Background 5

Source GDJ

Fancy Deboss #177
 Fabric  CC BY-SA 3.0

Luxury pattern, looking like it came right out of Paris.

Source Daniel Beaton