I got mine at Hobby Lobby. You can also get it at Michaels or at an Art Store. Heck ya can also find it at Wally World. I just get the 70% alcohol for a $1.00. Pour the alcohol into a clean container. put about 25- 30 drops of ink into the alcohol container then pour the fresh alcohol into the original bottle. Put the cap on tight then shake it up to mix well. Get ya an old car and a fresh paint brush and start Weathering.
I have done just washes of the Ink solutions. I have added chalk to areas of the car then washed it with the ink. I have also added paint to the alcohol for different effects. Weathering is one of the hobbies sidetracks that I love to do. Ya can have somany variations to your cars. Just take a look at the next passing train and see all of the variations there is. Kevin