Free Online Graph Paper

You can download Free Online Graph Paper / Grid Paper PDFs

They have a number of different 8-1/2 x 11 and 11 x 17 sheets, with black, grey, graph blue, and red lines, with various line weights and lines per inch, and you can customize your own by choosing document size, Minimum Border Width (inches), Grid Line Weight (points), Grid Spacing (lines/inch), and Grid Color (Black - Light Grey - Light Blue
Red - Blue - Green).

They also have Metric, Multi-Width, Asymmetric, Dots, Iso-Dots, Hexagonal, Hex Dot, and Celtic Knot / Celtic Knotwork Graph Paper.

Hat tip to Tech Smores