Soft Circle Scales #113
 Light  CC BY-SA 3.0

Japanese looking fish scale pattern.

Source Ian Soper

 More Textures
Background pattern 6 #225
 Noise  CC 0

Another fairly simple design drawn in Paint.net and vectorized in Inkscape.

Source Firkin

Prismatic Abstract Geometric Background 4 No Black #441
 Dark  CC 0

Prismatic Abstract Geometric Background 4 No Black

Source GDJ

Tessellation 15 (colour) #2222
 Blue  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

Retro Squares Background #414
 Noise  CC 0

Retro Squares Background

Source GDJ

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

Background pattern brown #1945
 Brown  CC 0

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

Source Firkin

Prismatic Basic Pattern 2 No Background #447
 Noise  CC 0

Prismatic Basic Pattern 2 No Background

Source GDJ

Retro Circles Background 6 #428
 Noise  CC 0

Retro Circles Background 6

Source GDJ

Carbon Fiber Big #326
 Carbon  CC BY-SA 3.0

Bigger is better, right? So here you have some large carbon fiber.

Source Factorio.us Collective

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

Type #276
 Dark  CC BY-SA 3.0

The perfect pattern for all your blogs about type, or type-related matters.

Source Atle Mo

Background pattern 227 (colour 6) #2309
 Red  CC 0

A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.

Source Firkin

Maze-seamless pattern #2555
 Grid  CC 0

This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.

Source Yamachem

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

Prismatic Abstract Line Art Pattern Background

Source GDJ