one of the first thing I learnt from my acrylic teacher was the 30% rule....you should never have more than 30% water when using acrylics......in the sunset painting I'm a little concerned we are using more than that when doing the sky. Should I change to glazing medium rather than water.....I think for learning exercise the water is ok but I am worried if someone used the same method in a painting for sale that the paint will peel off with time.Anyway, let me know what you think.
ThinningOPEN Acrylics can be thinned and extended with OPEN Thinner, OPEN Medium, water, or other GOLDEN Mediums. For most painting techniques the following guidelines are recommended: OPEN Thinner will reduce the viscosity while still preserving the optimal working time. Since OPEN Thinner contains no binders, limit additions to a maximum 3:1 ratio of 3 parts paint to 1 part OPEN Thinner to maintain film integrity. OPEN Medium is useful when a more fluid application is desired while maintaining the working properties and extended open time. Can be added in any ratio.Water will very rapidly reduce the viscosity of the paint, but will not preserve the extended open time. To maintain film integrity limit additions to a maximum 2:1 ratio of 2 parts paint to 1 part water.Faster drying GOLDEN Mediums can be added in any ratio to OPEN Acrylics to modify viscosity as well but will lower the open time in proportion to the ratio. For washes and stains on porous and absorbent grounds, one may exceed the above ratios, although the resulting paint films will become increasingly fragile and water sensitive. To later preserve these works, they will need to be properly framed and protected in ways similar to watercolors, or the surface will need to be consolidated with a layer of acrylic medium or an isolation coat prior to varnishing.Daler Rowney:When thinning down acrylic colours with water, the general rule is not to exceed more than 50% water. If the colour mix has more than 50% water it starts to lose its adhesive properties and will not be durable enough and will most likely start to peel. However, when it comes to acrylic mediums there are no such rules and you can add as much medium as you like to achieve the effects you desire. This is because acrylic mediums are made with acrylic resin as their base, which is the ‘glue’ or binder used in all acrylic colours.then they also say this with regards to using acrylic paint for airbrushing:System 3 Original should gradually be thinned with water, about 1 to 1 by volume to produce a milky consistency, to work effortlessly in your airbrush.
I have been painting in Acrylics for many years and still have in my possession my very first demo painting when I started teaching 27 years ago. In fact it is on the wall in my lounge. I've done many commissions and many acrylic paints during this 27 year period and have never once even given the water amount a thought - just thinned to the consistency I needed at the time. Not one of my paintings have ever shown the slightest sign of deterioration, let alone the peeling factor. The Makes I used was originally Atalier (long, long before the Interactive) and then Daler Rowney System 3 and Grumbacher Academy. My MOTTO: don't add any more water than you need to.Another thing: I always add a varnish to my paintings after making sure that the painting is completely dry.Again, you are the master of your own painting, and you must follow your own instincts and what is best for you.If you are using one of the impasto gels then don't add more than 25% gel to paint volume. Any more than 25% will start to lighten the colour but not the break down of the binder.