The image depicts a seamless pattern made using a bird's face.
Source Yamachem
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
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
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.
Source Firkin
Alternative colour scheme. 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
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
A seamless texture of a rough concrete surface.
Source V. Hartikainen
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin