A seamless paper background colored in pale yellow.
Source V. Hartikainen
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Chevrons Pattern 5 With Background
Source GDJ
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner