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
Tessellation 15 #2223
 Dark  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

Cardboard #278
 Paper  CC BY-SA 3.0

A good starting point for a cardboard pattern. This would work well in a variety of colors.

Source Atle Mo

Background pattern 258 #2135
 Dark  CC 0

Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Retro Circles Background 5@2X #425
 Noise  CC 0

Retro Circles Background 5

Source GDJ

Handmade Paper #37
 Paper  CC BY-SA 3.0

White handmade paper pattern with small bumps.

Source Marquis

Soft Circle Scales@2X #114
 Light  CC BY-SA 3.0

Japanese looking fish scale pattern.

Source Ian Soper

Woven #290
 Dark  CC BY-SA 3.0

Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.

Source Max Rudberg

Lined Paper@2X #363
 Stripes  CC BY-SA 3.0

The classic notebook paper with horizontal stripes.

Source Are Sundnes

Seamless Colorful Floral Pattern Background #256
 Fabric  CC 0

PDP

Source GDJ

Prismatic Snowflakes Pattern No Background #411
 Light  CC 0

Prismatic Snowflakes Pattern No Background

Source GDJ

Background pattern 333 #1741
 Noise  CC 0

The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i

Source Firkin

Background pattern 251 (colour 2) #2166
 Yellow  CC 0

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

Source Firkin

Background pattern 252 (colour 4) #2159
 Light  CC 0

Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin