A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
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
A new one called white wall, not by me this time.
Source Yuji Honzawa
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
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
More in the paper realm, this time with fibers.
Source Jorge Fuentes
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Polka Dots Mark II No Background
Source GDJ
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This one needs to be used in small areas; you can see it repeat.
Source Luca