Creative Techniques: Open Acrylic Paints
One of the newest paints around is called “Open” Acrylic paints. This latest formulation by Golden Artist Colors is the result of a complicated formula that allows an extended open time for painting. This paint is ideal for exploring techniques such as plein air, glazing, portraiture, glazing, softening edges, shading and creating fine detail.
Open Acrylics remain wet on the palette for a long period of time without having a skin form on its surface. You can mix Open paints in Gels and Mediums and with other paints with different consistency. If you mix the Open acrylics with Heavy Body or Fluid Acrylics you will accelerate the drying time of the Open Acrylics. Of course, when you are mixing a product with another thicker or thinner product, the properties of one product will affect the other. So even though you can intermix Heavy body paints or Fluids with Open acrylics, the different thickness of the paints will affect the consistency of your Open paint as well as the drying time. If you want to maintain the maximum working time of the Open Acrylics alone you need to use the Open Medium, the Open Gel or the Open Thinner on a non-absorbent surface.
There are many ways in which you can use this specialty product. I love this product for monoprinting, layering and blending. The ability to blend allows you to manipulate your edges and create smooth transition areas. You need to use Open acrylics in a thin manner or it will take weeks to dry properly. Open Acrylics are wonderful for blending as they stay “wet” and blendable for many hours even days! As long as the paint feels slightly tacky you can add water to continue to reopen layers and continue layering and blending. Once this time has been exceeded you can reactivate the layers using Open Thinner, Medium or Gel into the paint. Of course, if you work in a high humidity area and are using non-absorbent surfaces or a surface sealed with gel or medium this will also work to slow down the drying time. You can also dampen an absorbent surface with water or with a layer of Open thinner or Open Acrylic Medium first and this will allow you to work a nice wet in wet /blending technique.
However, if you want to speed up the drying time, you can use a hair dryer, paint on an absorbent surface, keep your paint film thin or, as mentioned above, mix the Open acrylics with regular Heavy Body or Fluid paint.
When painting over a recently worked area, you need to work gently over that area as there is a potential for reactivating the paint film. You can apply a thin coat of GAC 500, Fluid Matte Medium or an isolation coat (2 parts Soft Gel gloss to 1 part water) to create an “isolating” layer.
One technique you can use to create a faster drying layer is to put Acrylics, Gels, Pastes and Mediums down first. This now becomes your underpainting (textured or not). Once this layer is dry, you can now overpaint with Open Acrylics. This non-absorbent surface now allows you an optimal working time to blend, glaze, mange your edges, etc… If you are interleafing multiple layers, you must make certain that your Open Acrylics has fully coalesced.
So how do you determine what drying phase you are in?
The wet phase is when the paint retains the look and feel of coming from the tube. The workable stage is when the paint is thickening but is still able to “move”. Following the workable stage, there is a subsequent time where you can apply more paint layers without disturbing the “underpainting” yet if you care to blend the two layers it is still possible. That is the still can be reopened stage. The next stage is the touch dry stage and manifests itself as a slight surface tackiness. It is more difficult to re-open the paint film and you must proceed with caution if you attempt to move the film surface. The final phase is the locked down stage where the paint is immovable and water resistant.
Knowing when to use water versus the Open Thinner, Open Medium or Gel is very useful. Water can be used in the early stages to keep the paint moving but it will rapidly reduce the paint viscosity. Water will not, however, extend the paint working time. Eventually, to continue working the paint it will require the Open Thinner which will reduce the viscosity as well but will optimize the open working time. The Open Medium will more readily keep the fluidity of your paint and extend the open time as well. The Open Gels, Mediums and Thinners allow an artist to play with transparency or opacity, viscosity (thick/thin) and flow all the while allowing you a substantial working time. Priceless!
Open Acrylics will remain workable for hours even days on a non-absorbent surface such as glass or an enamel butcher tray but these surfaces need to be covered. To avoid skinning, you need to mist with Open Thinner every few hours to maintain blendability or mist with water every 15-30 minutes. If you are working in a Plein Air situation, try and find a shaded space protected from the wind and mist periodically and cover your paints if they are not in use. If your paint starts to feel tacky put a small amount of Open Thinner to reactivate the paints. Another bonus is that if you accidentally leave your brushes out with paint on them for a couple of hours, they can still be cleaned by soaking them in Open Thinner initially, then soap and water.
Having raved about the lengthy drying time the next item to consider is the varnishing time. Golden Artist Colors recommends that if you have used Open Gel or Medium or used lots of layers, your painting should dry for a minimum of 30 days prior to the application of a varnish, and a minimum of 2 weeks before application of an isolation coat. If you have used thick impasto type applications a longer drying time is recommended.
Finally, Golden Artist color has a very comprehensive product descriptor for Open Acrylics. I highly recommend you visit their website for more technical details. Source: goldenpaints.com/technicalinfo_openBack