Background pattern 306 (colour 2) #1881
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

 More Textures
Fabric pattern 2 (colour 5) #2392
 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

Seamless Cardboard Texture #1212
 Cardboard  CC BY-SA 3.0

A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.

Source V. Hartikainen

Diamond pattern (colour 5) #2281
 Red  CC 0

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

Source Firkin

Prismatic Geometric Tessellation Pattern 4 No Background #557
 Noise  CC 0

Prismatic Geometric Tessellation Pattern 4 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

Graphy #350
 Grid  CC BY-SA 3.0

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

Source We Are Pixel8

Medic Packaging Foil@2X #377
 Light  CC BY-SA 3.0

8 by 8 pixels, and just what the title says.

Source pixilated

Padded #61
 Dark  CC BY-SA 3.0

A beautiful dark padded pattern, like an old classic sofa.

Source Chris Baldie

leaf seamless pattern #2262
 Blue  CC 0

The image depicts a tiled seamless pattern.The tile represents four leaves aligned every 90 ° , which may look like a bird or a dragon .The original leaf design is from a Japanese old book.

Source Yamachem

Colorful Floral Background@2X #480
 Noise  CC 0

Colorful Floral Background

Source GDJ

Prismatic Dots Background 3 #505
 Noise  CC 0

Prismatic Dots Background 3

Source GDJ