I started using acrylic a long time ago. All the murals I/we produced we done with emulsion wall paint, a form of acrylic. It is watery, pastel(they have a white base to improve opacity) and transparent(its cheap). We usually paint everything 2-3 times over to get the opacity we want. This is good for beginners. As beginners can’t judge values and colors as well, they might get a few spots wrong in the first layer and then get them right in the 2nd or 3rd layer.
When you improve as an artist, you will start to feel annoyed at the additional layers you have to do because they become repetitive. For a beginner, every layer is an improvement. For the professional, every layer needs to play a role.
Once you are experienced, you will appreciate finishing your work in just one layer. It saves a lot of time.
For murals, synthetic brushes are preferred. If the softest brushes are watercolour brushes. Then mural brushes are slightly harder. I prefer those that have an orange bristle. They are very suitable for murals.
For canvas paintings, a slightly stiffer brush compared to that are better. The Daler Rowney’s Cryla range are good for this purpose. Of course, for impasto, bristle brush is still necessary.
There are glazing mediums to achieve transparency for acrylics. Water can be used too. However, it takes a different skill to use water for glazing because of drip marks and puddles. We usually constantly brush the glaze over and over, spreading it to dry each time and also to stop it from dripping and puddling. Glazing mediums are thicker and its easier to use. They are expensive though. Most of the expensive materials/tools in art can be substituted with technique.
Acrylics dries fast. Some really fast but generally just fast. If the paint is the consistency of a cake, it will have a dry skin in just 15 minutes. For beginners, it is an advantage. Mistakes can be cover, reworked and changed. When it comes to blending, some artists use a retarder to slow the paint from drying down but some just work fast. For precise gradients with little tonal or color change, it can be a challenge because acrylics dries darker. It can cause the artist to be in a constant loop of painting with a spot being lighter or darker all the time.
The key to blending is to determine the area that needed blending and work the entire area precisely in one short session. Repeat only when dry if necessary. A mop brush is best for this.
Acrylics are easy to clean up. Paints on palette can be left to dry and peeled off after that. Brushes must be kept in a water jar during work. It can be cleaned with water and hair shampoo if necessary. Brushes can be soften with a hair conditioner.
Paintings done in acrylic dries to a plasticky finish compared to oils. Its almost like comparing plastic to metal finish. Matte vs gloss.
If you are transitioning from acrylic to oils, there are challenges specific to you.
- Clean with turpentine/spirits/solvents. Paint with oil(linseed/sunflower/safflower). This is the biggest difference that intimates an artist who wants to start with oil painting. So just remember – you only need the solvents when you are cleaning your brush, usually at the end of the session. For the most part, you use oil to paint. In acrylics you dilute with water, here you dilute with oil.
- The darn smell. For god’s sake, keep the solvent’s closed until you need it. Do not be fooled by odourless solvents. Just because it has no smell doesn’t meant its not poisonous.
- Transparency of paints matter in oil painting. In acrylics, you take advantage of transparent paints(red, yellow, green) and use them to glaze. In oil painting, they become even more important. Transparent paints do not get muddy when you overlay them and you use transparent paints in shadows. Not only that, you need to use synthetic brushes when it comes to transparent paints.
- Beginners paint with thin layers and adjust colors and tones slowly. This helps because if paint were placed boldly, they can get muddy if they are inaccurately mixed. Professionals place every brush stroke with the correct tone, color and chroma in the correct location. They can immediately paint thickly if they wish.
- It is constantly wet. Do you remember when acrylics weren’t dry and it’s difficult to blend because the paint kept being removed back and forth from the canvas? It is like that with oils. Blending soft gradients need soft mop brushes(hake brushes). Soft edges just need an overlapping brush stroke. If you can paint all sorts of gradients with acrylic on a glass plate, you will do just fine in oils.
- Fat over lean, lean over fat. What?
Oil painting can get technical fast. It is in fact similar to acrylics. In acrylics, you start with a watery layer to sketch in roughly. Then you block in with thicker paint and finish with slightly watery paint to detail areas. In oils it is the same, you start with a mix of oil and paint to sketch. It will wet the canvas and ready it for more paint. Then you block in with transparent paint thinly, followed by thick paint and finished with mix of oil and paints for detail areas. As long as you do not use solvents in the middle of the painting, the paint film should be stable enough.
- Mistakes must be scraped away. If you make a mistake, scrape it away with a paint knife and reapply a fresh mix. Keeping mistakes will make the painting muddy.
- Brushes can be cleaned with solvents, then rinsed in oil soap and dried.
- Know your oils, paints and mediums.
- Linseed oil – common painting oil. Sunflower and Safflower oil – slow drying oil. If you want your painting to stay wet longer, use the appropriate oil.
- Check paints transparency when you purchase them. I have a few tubes of yellow paints that are incredibly expensive simply because they are opaque. In essence, dark colors should be transparent and colors that are light should be opaque.
- There are plenty of painting mediums going around. They mostly manipulate the drying time and consistency of paints similar to acrylic painting mediums. There are some mediums that allow the paint to flow better but still remain sticker and these are good for detailed work. Some mediums can make the paint become more saturated for the expense of a faster drying time. I find most of these redundant as having all sorts of different chemicals on the canvas can introduce complications in the painting film as it dries.
- Painting medium – The only painting medium you will need is linseed oil and calcium carbonate. Mix them in varying ratio in order to create the medium that you want. Higher ratio of oil vs CC will create a nice smooth painting medium. The exact opposite are good for impastos.
Oils are wonderful for a few specific reasons as well :
- They dry the same value. This is a huge advantage when it comes to precise blending.
- They are off a better quality compared to acrylics. You can invest in expensive paint brands and then extend the quantity of the paint provided with the painting medium. The paints are of such good quality that you can easily triple the size of a tube.