Background pattern 19 (outline) #204
 Light  CC 0

A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.

Source Firkin

 More Textures
Wood@2X #50
 Wood  CC BY-SA 3.0

Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com

Source Atle Mo

Prismatic Dots Background 4 #507
 Noise  CC 0

Prismatic Dots Background 4

Source GDJ

Paper 3 #31
 Paper  CC BY-SA 3.0

Light gray paper pattern with small traces of fiber and some dust.

Source Atle Mo

Background pattern 66@2X #478
 Wall  CC 0

A background pattern drawn in Inkscape.

Source Firkin

Mirrored Squares@2X #124
 Dark  CC BY-SA 3.0

Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.

Source Atle Mo

Fabric pattern 2 (colour 6) #2391
 Fabric  CC 0

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

Concrete Wall 2@2X #80
 Wall  CC BY-SA 3.0

A light gray wall or floor (you decide) of concrete.

Source Atle Mo

Retro Circles Background 5 No Black@2X #427
 Noise  CC 0

Retro Circles Background 5 No Black

Source GDJ

Vintage pattern #1958
 Grid  CC 0

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

Source Firkin

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

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

Japanese looking fish scale pattern.

Source Ian Soper

Seamless Core Pattern 2 #166
 Dark  CC 0

Seamless Core Pattern 2

Source GDJ

snow crystal seamless pattern #2467
 Blue  CC 0

The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975

Source Yamachem