A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Plywood Web Background background image for use in web design.
Source V. Hartikainen
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso
Prismatic Polka Dots 3 No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
White circles connecting on a light gray background.
Source Mark Collins
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Colourful background achieved with gradient fills.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin