More Textures
Background pattern 5 #224
 Noise  CC 0

A pattern drawn in Paint.net and vectorized in Inkscape.

Source Firkin

Background pattern 223 (colour 6) #2348
 Yellow  CC 0

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

Source Firkin

Prismatic Polyskelion Pattern No Background #394
 Light  CC 0

Prismatic Polyskelion Pattern No Background

Source GDJ

Graphy #350
 Grid  CC BY-SA 3.0

Looks like a technical drawing board: small squares forming a nice grid.

Source We Are Pixel8

Tessellation 15 (colour 4) #2219
 Green  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

Background pattern 261 #2076
 Dark  CC 0

Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861

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