Background pattern 215 (colour 3) #2369
 Pink  CC 0

A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.

Source Firkin

 More Textures
Sports car pattern #2442
 Red  CC 0

A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Pattern generator #161
 Noise  CC 0

A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.

Source Lazur URH

Prismatic Abstract Line Art Pattern Background@2X #566
 Dark  CC 0

Prismatic Abstract Line Art Pattern Background

Source GDJ

Background pattern 231 #2301
 Dark  CC 0

A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Prismatic Curved Diamond Pattern 5 No Background #543
 Diamond  CC 0

Prismatic Curved Diamond Pattern 5 No Background

Source GDJ

Background pattern 249 #2179
 Blue  CC 0

To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Prismatic Groovy Concentric Background No Black@2X #452
 Noise  CC 0

Prismatic Groovy Concentric Background No Black

Source GDJ

Diagonal Noise #181
 Fabric  CC BY-SA 3.0

A simple but elegant classic. Every collection needs one of these.

Source Christopher Burton

Prismatic Curved Diamond Pattern 2 No Background #538
 Diamond  CC 0

Prismatic Curved Diamond Pattern 2 No Background

Source GDJ

Prismatic Polka Dots Mark II No Background@2X #531
 Noise  CC 0

Prismatic Polka Dots Mark II No Background

Source GDJ

Seamless Colorful Floral Pattern Background #256
 Fabric  CC 0

PDP

Source GDJ

Gold Scale #284
 Light  CC BY-SA 3.0

More Japanese-inspired patterns, Gold Scales this time.

Source Josh Green

Prismatic Dots Background 5 #509
 Noise  CC 0

Prismatic Dots Background 5

Source GDJ

Cross Stripes #47
 Dark  CC BY-SA 3.0

Nice and simple crossed lines in dark gray tones.

Source Stefan Aleksić

Background pattern 41 #262
 Fabric  CC 0

A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.

Source Firkin