"Gold Buttons", Pale Yellow BG Pattern #1215
 Yellow  CC BY-SA 3.0

This yellow background consists of a pattern of glossy gold buttons arranged in polka dot style on a seamless texture. Here's a pale yellow background pattern. Feel free to use it for your needs!

Source V. Hartikainen

 More Textures
Robots #125
 Dark  CC BY-SA 3.0

And some more testing, this time with Seamless Studio. It’s Robots FFS!

Source Seamless Studio

Retro Squares Background #414
 Noise  CC 0

Retro Squares Background

Source GDJ

MBossed@2X #194
 Grid  CC BY-SA 3.0

Embossed lines and squares with subtle highlights.

Source Alex Parker

Background pattern 339 (colour 2) #1707
 Green  CC 0

The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Background pattern 221 (colour) #2346
 Yellow  CC 0

A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Brushed Alum Dark@2X #66
 Dark  CC BY-SA 3.0

Because I love dark patterns, here is Brushed Alum in a dark coating.

Source Tim Ward

Prismatic Floral Pattern 3 Variation 3 No Background #386
 Noise  CC 0

Prismatic Floral Pattern 3 Variation 3 No Background

Source GDJ

Small Crosses@2X #116
 Stripes  CC BY-SA 3.0

Sharp pixel pattern looking like some sort of fabric.

Source Dmitry

Retro Squares Background 4 #418
 Dark  CC 0

Retro Squares Background 4

Source GDJ

Fabric pattern 2 (colour 4) #2393
 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

Decorative divider 188 #2521
 Dark  CC 0

From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.

Source Firkin

Prismatic Abstract Line Art Pattern Background 2@2X #568
 Dark  CC 0

Prismatic Abstract Line Art Pattern Background 2

Source GDJ

Background pattern 302 #1894
 Red  CC 0

The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.

Source Firkin