Vichy@2X #72
 Light  CC BY-SA 3.0

This one could be the shirt of a golf player. Angled lines in different thicknesses.

Source Olivier Pineda

 More Textures
Small Crosses #115
 Stripes  CC BY-SA 3.0

Sharp pixel pattern looking like some sort of fabric.

Source Dmitry

Seamless Core Pattern 6 #170
 Dark  CC 0

Seamless Core Pattern 6

Source GDJ

Diamond pattern (colour 7) #2274
 Red  CC 0

From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Prismatic Polka Dots Mark II 2 No Background #532
 Noise  CC 0

Prismatic Polka Dots Mark II 2 No Background

Source GDJ

Decorative divider 253 #2064
 Dark  CC 0

From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.

Source Firkin

Colorful Paw Prints Pattern Background #260
 Noise  CC 0

pixabay.

Source GDJ

seigaiha subtle color #2278
 Pink  CC 0

This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .

Source Yamachem

45-Degree Fabric@2X #2
 Fabric  CC BY-SA 3.0

Medium gray fabric pattern with 45-degree lines going across.

Source Atle Mo

Decorative divider 217 #2233
 Dark  CC 0

Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.

Source Firkin

Prismatic Curved Diamond Pattern No Background@2X #537
 Diamond  CC 0

Prismatic Curved Diamond Pattern No Background

Source GDJ

Glass block pattern #2477
 Brown  CC 0

Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.

Source Firkin

Prismatic Curved Diamond Pattern 7 No Background #547
 Noise  CC 0

Prismatic Curved Diamond Pattern 7 No Background

Source GDJ

Iron Grip@2X #588
 Dark  CC BY-SA 3.0

Sounds like something from World of Warcraft. Has to be good.

Source Tony Kinard

Seamless Core Pattern #165
 Dark  CC 0

Seamless Core Pattern

Source GDJ

Tileable Wave Pattern 2 remix #2490
 Dark  CC 0

This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.

Source Yamachem

Retro Squares Background 8 #398
 Noise  CC 0

Retro Squares Background 8

Source GDJ

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