I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
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
The image is the remix of "wire-mesh fence seamless pattern" .This is a more minute version of it.Sorry for the file size.Using path>difference in Inkscape, I will cut out any silhouette from this pattern and create a "meshed silhouette".
Source Yamachem
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
The original enhanced with one of Inkscapes's filters.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Just like the black maze, only in light gray. Duh.
Source Peax
This is the remix of an OCAL clipart called "Rain on Window" uploaded by "pagarmidna".Thanks.This is a seamless pattern of raindrops.
Source Yamachem
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
"Beige Stone", Tileable Texture.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Floral Background No Black
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
The image is a design of blue glass.How about using it as background image?
Source Yamachem