Background pattern 250 (colour) #2171
 Yellow  CC 0

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

Source Firkin

 More Textures
Old Mathematics #43
 Stripes  CC BY-SA 3.0

This one takes you back to math class. Classic mathematic board underlay.

Source Josh Green

Black Linen 2@2X #104
 Dark  CC BY-SA 3.0

A new take on the black linen pattern. Softer this time.

Source Atle Mo

Abstract Arbitrary Geometric Background@2X #498
 Noise  CC 0

Abstract Arbitrary Geometric Background derived from an image on Pixabay.

Source GDJ

Background pattern 195 #2587
 Grid  CC 0

Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.

Source Firkin

Prismatic Abstract Geometric Background 2 No Black@2X #446
 Noise  CC 0

Prismatic Abstract Geometric Background 2 No Black

Source GDJ

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

Dark Blue Gray Wallpaper Texture #901
 Stripes  CC BY-SA 3.0

This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!

Source V. Hartikainen

Floral background 2 #380
 Wall  CC 0

Background formed from the original with an emboss effect

Source GDJ

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

Vintage tile background #2248
 Brown  CC 0

A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.

Source Firkin