Before colouring your jar, wash it in hot soapy water and dry it thoroughly. You want to remove any residue that could prevent the ink from adhering to the surface of the jar. Choose whatever pattern or design you want for your jar. You could choose regular shapes or stripes or circles – whatever you like. When you’re colouring, try to keep your ink to one layer.
This means not going back over the same area that you’ve already coloured because that second layer tends to lift off the first layer. Also, when you’re switching colours, try not to overlap. Not only will you lift the first colour, but if you go over top of blue with a yellow marker, you’re going to end up with blue ink on your yellow marker tip. Other than keeping your colours separate, there isn’t much more too it.