Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
From a drawing in 'Codogno e il suo territorio nella cronaca e nella storia'', Gio and Giarella Cairo, 1897.
Source Firkin
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Embossed lines and squares with subtle highlights.
Source Alex Parker
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
From an image on opengameart.org shared by rubberduck.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin