One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Colourful background achieved with gradient fills.
Source Firkin
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
White handmade paper pattern with small bumps.
Source Marquis
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen