Number five from the same submitter, makes my job easy.
Source Dima Shiper
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
White little knobs, coming in at 10x10px. Sweet!
Source Amos
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Looks like an old rug or a computer chip.
Source Patutin Sergey
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Remixed from an image on Pixabay uploaded by Prawny
Source Firkin
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen