There will inevitably come a time when you will need to thin down your acrylic paint. Now there are only two choices when you need to thin your paint; you can mix your paint with water or you can use a medium. Since acrylic paint is a water based medium, water is ok to use as long as you do not use more than 50% water. Any more than this and your paint can lose its adhesive properties. This can cause your paint to peel at a later date. Water can also weaken the color so that it isn’t as bright and saturated as it is straight from the tube.
If you prefer working with thinner colors, I suggest you either use a medium or purchase fluid acrylic colors. When a special medium is added to acrylic paint, it will not adversely affect the properties of the paint. If you purchase a good quality fluid acrylic, it will contain high pigment levels with high tinting strength and it will maintain its durability, flexibility and adhesive qualities. This makes fluid acrylics an ideal choice for spraying, pouring, dripping and staining.
I recommend Golden Fluid Acrylics if you wish to go this route. You can purchase them now by clicking the link below.