If you ever have occasion to use graph paper or any lined paper for that matter you will want to bookmark this site. You can create a pdf file with just about any kind of lined paper you could imagine in just about any size and color you could desire.
How do I use this free service?:
Visit the Free Online Graph Paper page on the Incompetech site and select the type of lined paper you want to print. Click on the appropriate link and you can then set the line spacing, color, page size, and more. After you click the GetPDF button your creation will be displayed as a pdf file. You can print as many pages as you need and you can also save the pfd file so you can print more later.
I've only tested the service with Windows, but it should work with Linux and Mac also.
What are the risks in using this free service?:
There is no registration required and nothing is installed from the site so it should be about as risk free as you can get.