A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
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
Original minus the background
Source Firkin
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
This is the remix of "plant pattern 02".I changed the object color to white and the BG to purple.The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:jp.pinterest.com/pin/500744052301423641/
Source Yamachem
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed