Tessellation 16 (colour 6) #2210
 Colorful  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
Fabric pattern 3 (colour 3) #2385
 Fabric  CC 0

Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Background pattern 314 (colour 5) #1835
 Pink  CC 0

The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Broken Noise@2X #365
 Dark  CC BY-SA 3.0

Beautiful dark noise pattern with some dust and grunge.

Source Vincent Klaiber

Prismatic Curved Diamond Pattern 3 No Background@2X #540
 Diamond  CC 0

Prismatic Curved Diamond Pattern 3 No Background

Source GDJ

Background pattern 262 #2075
 Dark  CC 0

Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.

Source Firkin

Axiom Pattern@2X #331
 Grid  CC BY-SA 3.0

Not even 1kb, but very stylish. Gray thin lines.

Source Struck Axiom

Prismatic Groovy Concentric Background 4 #461
 Noise  CC 0

Prismatic Groovy Concentric Background 4

Source GDJ

Medic Packaging Foil #376
 Light  CC BY-SA 3.0

8 by 8 pixels, and just what the title says.

Source pixilated

Background pattern blue #1949
 Blue  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Seamless arrow pattern remix #2528
 Dark  CC 0

Similar to original, but without gaps in between the arrows. This seamless pattern was created from a rectangular tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Seamless Core Pattern 6 #170
 Dark  CC 0

Seamless Core Pattern 6

Source GDJ