Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
A nice and simple white rotated tile pattern.
Source Another One
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Fix side and a seamless pattern formed from circles.
Source SliverKnight
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