Tessellation 16 (colour 6) #2210
 Colorful  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

 More Textures
Concrete Wall 3 #93
 Light  CC BY-SA 3.0

All good things come in threes, so I give you the third in my little concrete wall series.

Source Atle Mo

Zig-zag pattern 4 #2415
 Grid  CC 0

A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin

"Dark Brick Wall", Background Pattern #1024
 Stone  CC BY-SA 3.0

Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.

Source V. Hartikainen

Background pattern 224 (colour 5) #2338
 Colorful  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Batik Parang Rusak Seamless Pattern(faqeeh)-remix #2450
 Dark  CC 0

As the original image 's page size is too large for its image size, I remixed it.

Source Yamachem

Prismatic Polka Dots Mark II 2 No Background@2X #533
 Noise  CC 0

Prismatic Polka Dots Mark II 2 No Background

Source GDJ

Green Fibers #91
 Dark  CC BY-SA 3.0

The green fibers pattern will work very well in grayscale as well.

Source Matteo Di Capua

Felt@2X #301
 Wall  CC BY-SA 3.0

Got some felt in my mailbox today, so I scanned it for you to use.

Source Atle Mo

Prismatic Curved Diamond Pattern 4 No Background #541
 Diamond  CC 0

Prismatic Curved Diamond Pattern 4 No Background

Source GDJ

Patchwork Quilt Pattern Background #228
 Noise  CC 0

PDP

Source GDJ