This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
It looks very nice I think.
Source V. Hartikainen
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
An alternative colour scheme to the original seamless pattern.
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
From an image on opengameart.org shared by rubberduck.
Source Firkin
Prismatic Geometric Pattern Background
Source GDJ
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
This one has rusty dark brown texture.
Source V. Hartikainen
Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.
Source V. Hartikainen
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ