watercolour papers come in-many different sizes, weights, Sizing is particularly important in these papers because it allows the colour to stay on the surface as the water sinks in. This gives watercolours their brilliance, which would be lost if the colour were to sink below the surface with the water. An additional benefit is that the colour can be lifted and reworked because of its accessibility on the surface of the paper.
Hot press has a hard, smooth surface as it is ‘ironed.’ and a very fine tooth. This finish is excellent for soft drawing materials, pen and ink, brush linework, wash, and airbrush. This type of paper is not as popular for traditional watercolour techniques as it is hard to paint on as the paint tends to run
cold press Cold press, or semi rough, is the most popular . Cold-press finish is excellent for traditional watercolour technique because of its moderate texture. This finish is also excellent for charcoal, pastel, and paint sticks.
The ‘weight’ of the watercolour paper is also an important consideration! If, say, you want to use a lot of water, paper in the 300 (640gsm) to 400 pound range, is sturdy and absorbs water better.
Papers are sold in weights. This is the thickness of the paper. Papers that are less than 300-lb or 640gsm (grams per square meter) most will need to be stretched before painting or the paper will buckle when wet making painting difficult and the paint will dry in the hollows.
To Stretch The paper Soak the paper in the water until it is saturated, this will take less than a minute. Place the paper onto the board and smooth it out from the center to the edges.
some papers come pre-sized (Arches for example )
When using acrylics as watercolour all the above applies if your using straight from the tube or with just a little diluents then then any good quality paper over 90 lb or 190 gsm will be just fine
Having said that my location makes finding paper somewhat challenging, and so I just have to learn by experimenting what it can and cannot do and work with that.
Acrylic Paint
Acrylic Paint can be used for painting on canvas, board, paper, panels, glass, wood, metal, fabrics, and ceramics or virtually any prepared surfaces. They are highly pigmented and are usually of a paste consistency similar to oil paint so if used thickly preserving brush strokes or finger smudges. They can be used with a variety of painting techniques, including impasto (Thick) and knife (or what ever comes to hand) painting.
Cheaper paints have lower pigment concentrations, and have poorer lightfast characteristics, but can be generally be used for the base layer on a large painting .
dry fast but still allows time to work and to blend colours When dry, acrylic paint is generally non-removable. Acrylics dry fast but there is time to work and to blend colours
Acrylic vs Watercolour
Acrylic artist paints can be diluted with water and used as watercolour paints, but when the paint dries it can't be lifted of like watercolour paints.
Acrylics paints dry slightly darker, while watercolours dry lighter and the colour is sometimes unpredictably.
There is no white in watercolour painting, the white comes from the paper you are working on. So can be difficult to produce prominent white high-lights without preplanning or masking but a dab of white gouache is usually exceptable.
When using Acrylic paint as a transparent medium, similar to watercolour. Acrylics do have an advantage over watercolours in that you can use a number of thin washes over one another without disturbing the colours underneath
When using washes with acrylic you will get a hard edge this is usually a disadvantage but may be desired..
I like to use acrylic paints because they are so versatile and can be used just like watercolour. Acrylic paint is water-based meaning it dissolves in water.
Acrylics paints can be used in place of watercolours because acrylics dry closer to the desired colour which is slightly darker, while watercolours dry lighter and the colours are sometimes unpredictably.
Having said that I prefer to use watercolour paints for watercolours, I mostly use Winsor & Newton Cotman colours, and Koi water colors.
The wet on wet is a technique favored by watercolour artists. by applying a layer of colour to the paper while it is wet, then adding another colour. The two colours create soft subtle variations in colour. Later adding the foreground details. With acrylic you can also do the reverse where you add a layer of colour
