Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
A yellow tiled background... Blurriness, bokeh effect and rectangles pattern in one mix.
Source V. Hartikainen
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
The image a seamless pattern of a wire-mesh fence.I want you to use this pattern as a lower layer.
Source Yamachem
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Continuing the geometric trend, here is one more.
Source Mike Warner
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
This is a hot one. Small, sharp and unique.
Source GraphicsWall
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
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
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo