Where can I buy a tool to make wood grain?

Most specialty paint store carry them as does Michael's, Hobby Lobby and Joann's... you will probably find them at Home Depot or Lowe's in the paint dept..... if it doesn't jump off the wall at you.... just ask.

if this is the project ask the creator for the information.https://www.hometalk.com/diy/living-room/furniture/faux-wood-grain-looks-so-cool-on-a-glass-table-37184870?r=2

They sell them in the paint area of a hardware store, or in the furniture refinishing area of a hobby shop. They are also sold on-line.

The trick is to learn how to use the tool. With the curved tool, dragging while rocking from one side to the other will get a more random grain. Some grain should be straight, and a common mistake is having too much curved grain. Here is a Hometalk video that gives a quick and dirty lesson. https://www.hometalk.com/diy/paint/faux-wood-grain-paint-technique-27949293

Here is an article describing several types of wood graining tools. https://www.doityourself.com/stry/5-wood-graining-tools-explained

Faux wood grain can take years to master. Be sure to study the natural wood you wish to mimic. Look for online how-to articles like this one: https://www.house-painting-info.com/articles/faux-oak-wood-grain/ Always practice before you start your project.

Amazon sells the tool https://www.amazon.com/Allway-GT3-Graining-Tool-Set/dp/B003BKPRNQ/ref=sr_1_1?ie=UTF8&qid=1529067220&sr=8-1&keywords=Wood+grain+tool And they have other options as well. roller style, combs, rocker style, tree bark - looks like they could be fun

You can make your own cardboard comb. Use 6 ply cardboard, and with a craft knife make grooves or tear off about six different pieces for varying effects. Full details on how to do this on pg. 98 of this book: The North Light Book of Creative Paint Finishing Techniques by Ray Bradshaw. Try the library or abebooks.com for used copy.