Background pattern 306 (colour 2) #1881
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

 More Textures
Starting Diamond Shape@2X #138
 Light  CC 0

Simple blue and line to mix.

Source SliverKnight

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

Prismatic Curved Diamond Pattern 2 No Background

Source GDJ

Background pattern 339 #1709
 Dark  CC 0

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

Source Firkin

Background pattern purple #1946
 Colorful  CC 0

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

Source Firkin

White Paperboard #374
 Fabric  CC BY-SA 3.0

Could be paper, could be a Polaroid frame – up to you!

Source Chaos

Hexagonal pattern (colour) #2378
 Yellow  CC 0

A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.

Source Firkin

Prismatic Chevrons Pattern 5 With Background #469
 Dark  CC 0

Prismatic Chevrons Pattern 5 With Background

Source GDJ

Background pattern 9 (colour) #214
 Noise  CC 0

Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net

Source Firkin

Tessellation 16 #2215
 Yellow  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

Vintage pattern #1960
 Grid  CC 0

Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.

Source Firkin

Background pattern 274 #2041
 Dark  CC 0

Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.

Source Firkin