There are different types of grounds depending on the surface to work on, from smooth to textured. I have studied about grounds after attending Tim (Painting techniques expert and tutor) teaching sessions of Methods and Materials. Grounds traditionally have some tooth to make the paint adhere better. I choose grounds depending on the support that I am working on.I majorly work on canvas and canvas expands and contracts so it requires a flexible ground. A ground can be any color, although white is the most commonly used. However, I find it difficult to get an accurate reading of values and colors on a bright white canvas. Since, due to simultaneous contrast, most colors appear darker on a white surface than they do when adjacent to other colors, I have learned that many artists prefer to tone their canvases before painting. Hence, To create a colored ground, I prefer to add color to the primer or gesso or a layer of color applied over the priming/ Gesso.
Also, I have even tried an absorbent ground that pulls in or absorbs a paint, rather than letting it sit on the surface. Golden Absorbent Ground is an acrylic ground that created a porous paper-like surface when applied in a thin layer over acrylic gesso.
But why use Gesso ?
Gesso in general and to me my initial coat applied onto a surface such as canvas or wood before I paint or draw on it. The purpose of gesso is to protect the support from the paint, some of which contain components that could damage it. Gesso also provides the surface for the paint to stick to and affects the absorbency of the support. Gesso dries to a matte surface that provides adhesion for the paint. And then to get a more smoother finish, I sometimes sand it.
A high quality acrylic gesso brands explains it as – A gesso contains an acrylic polymer medium that serves as a binder (rather than glue) along with chalk, a pigment (usually Titanium white), and chemicals used to keep the surface flexible and avoid fading.
Moreover It is known that acrylic paint is water-based and thus water-soluble when wet, so water can be used to thin it. But as to how much I can thin it, is a question to me and so, several variables come into play, such as quality of paint, the surface, and whether I using a medium (and of what kind).
Some online sources advise not to mix acrylic paint with more than 50 percent water. Any more than this may cause the polymer in the acrylic paint to break down and lose its adhesive qualities, resulting in peeling or flaking at some stage.
Although I majorly use use less than 30 percent water or may 30-35% that helps me eliminate any concerns about having a negative effect on the binding properties of the paint.
Higher-quality professional-grade acrylic paints like golden and Holland can actually hold more water than lower-quality student-grade paints because the professional-grade paint starts out with a higher pigment-to-binder ratio.
Painting With Mediums
I feel mediums are a great resource to an artist and a student like me to change the viscosity of the paint dramatically while still retaining its chemical integrity, or to thin the paint with one of the many different types of mediums I use, like glazing, sand and grain texture paste, matte gel, gloss and varnish, levelling gel etc. With acrylic paints to give different effects, such as thinning, thickening, adding texture, glazing, or slowing the drying time.
And the good part is I have the liberty to mix in as much acrylic medium as I like because acrylic mediums have the same resin in them that makes the paint stick. Golden, for example, describes its mediums as "colorless paint”, and I always end up using 40% of the medium mixed extremely properly for 5-10 mins in order to make the paste diluted completely. Thus this helps me to make a flat application of colors on canvas, however, to achieve complete flatness I often use 2 – 3 layers of medium thickness paints. For me, each step of producing a painting from preparing the surface- making colors to drawing and painting with mediums till doing finishing touches required almost equal amount of time and energy. My work might seems simple as a final outcome but It has also always been important to me to learn about the other aspects of learning painting and This course has given me that time and momentum to widen my mind map in terms of answering few question about why to paint in a certain style and medium that I painting now.