Glass is a non-absorbent painting support which does not allow paint to easily adhere to it – apart from through the paint’s own drying process. 4×8 plexiglass
For this reason the outlines of a subject painted on glass need to be simplified when applied to an extremely smooth glass surface. Simplifying a subject does not necessarily detract from the end result after the painting is completed and the final result can often have an appearance similar to that of naive art in relation to composition and form and a certain number of other details. Many artists may find that such simplification can actually be very appealing.
Working the paint or changing outlines without smudging the surrounding areas of undried paint may require some concentration in the beginning, as well as a certain amount of skill, but with patience and the development of their skills using this painting technique, artists will find that applying and mastering the use of glass as a support will become easier as time progresses.
MATERIALS REQUIRED FOR PAINTING ON GLASS
Choose clear unflawed glass (or plexiglass) in the shape and size you wish to use. In order to begin mastering the technique of reverse painting it is advised to choose smaller sizes to begin with.
It is important to use a paint that will adhere properly to the surface of the glass. Oil based paints or acrylics are often used for this reason.There are also opaque and transparent ceramic artist colours that have been especially manufactured for using on a non-absorbent surface. Metallic colours (eg. gold, silver or copper) can also be interesting to work with. There are an increasing number of new art products available today that may be suitable for painting on a non-absorbent surface such as glass.
To begin choose a selection of small or medium-sized paintbrushes with fine, flat and pointed tips. Larger brushes can be used for working on a larger scale. Artists can also use less conventional tools for applying paint if they wish, depending on the effects obtained through experimentation that may interest them.
Used for outlines (if required) and finer details. It can be an advantage to use interchangeable nibs suitable for creating both thick and thin outlines.
Ink for creating outlines on glass
The inks used need to be suitable for applying to a non-absorbent surface such as glass. As an alternative paint can also be thinned down into a more liquid form and used for creating outlines in which case attention must be given to to creating the right mixture of fluidity and thickness.
A painting palette or something similar to mix your paint on.
A palette knife -(optional) for mixing paint.
Artists paint cleaner or thinner – used for cleaning or sometimes for thinning, and depending on whether oil based or water-based paints are used.
A paint-drying agent – (optional) For mixing with paints to help speed up the drying process
Paper towelling or some clean rags
A mirror – (optional) can be used to check the progress of your painting while you are continuing to work. Place the mirror in a position where it will reflect your artwork from its viewing side.
Cellotape – or a similar average-width sticking tape
An easel – (optional) to prop your work on
A glass-cleaning product
PREPARING THE GLASS
Choose a piece of clear glass in the dimensions you would like to work with and check carefully to make sure the glass is neither scratched nor flawed. It is worthwhile remembering that a flaw in the glass itself will often detract from the finished appearance of a painting and may be impossible to remove after the completion of your artwork.
The sheet of glass that is to become your artwork constitutes the following:
(1) The ‘painting side’ – which is the side you will be painting on.
(2) The ‘viewing side’ – which is the side you will be looking at (or through) as you progress with your work and after it has been completed.
To render the cutting edges of the glass safe take a length of cellotape that will correspond to the length of one edge. Apply it carefully along that length (ideally so that it is folded equally over each side of the glass).
Repeat this procedure for the other 3 glass edges. The edge of the cellotape will also help mark the outer limits of your artwork.
Clean the surface of the glass thoroughly with a glass-cleaning product. Use paper towelling or any cleaning material that will not leave dust or threads on your painting surface.
Store the glass where it will be safe. If placed between sheets of newspaper it will be protected from scratches and dust.
Art products in liquid form that are suitable for creating outlines on glass may be readily available in some countries. Oil-based paint,water-based acrylic and ceramic paint can also be used for this purpose.In order to create fine lines these paints must sometimes be thinned down in order to use with a pen nib or similar line-drawing tool.
To prevent lines from being effaced too easily you can use a paint that is oil based for creating the outlines of your subject if the paint you will be applying over the top of it (after it has properly dried) is water based. Reverse this procedure if your outlines are created with a water-based paint.
Always use a liquid paint product that will provide the best adhesion possible to a glass surface.
Due to pen nibs clogging relatively easily, attention must be paid to cleaning the nibs regularly.
If you have a steady hand you can use a freehand method for applying outlines directly onto the surface of the glass.
Use an original subject for your painting (e.g. a drawing) and place this under the glass then copy it onto the glass surface.
Place a layer of carbon-paper on top of the glass then place your drawing on top of the carbon paper and with a pointed object trace the subject onto the glass. Be careful not to damage your original image (the image being copied) when using a pointed object.
A tracing table can be used for creating outlines. This is a table with a sheet of clear glass inserted into the top and with an electric light source situated beneath it. For those who frequently need to trace their work a tracing table can be very practical and useful.
You can omit outlines altogether.
APPLYING THE PAINT
Most artists have a preference for how to work when creating an artwork. Once it has been decided whether to work on a table or use a table-easel or a standing easel, it will be necessary to view the artwork regularly from its observation side in order to see its progress.
Some artists simply take the glass in their hands and turn it around to look at it directly from the observation side. Others prefer to use a mirror placed directly opposite their working area so that they can observe their progress while they paint.
Mixing and blending
If you are blending colours always do so on a palette or similar flat object before applying them to the glass. If colours are not well blended or mixed the result will be a streaky appearance in the paint on the observation side of the glass.
When creating a reverse painting on glass it is important to watch out for smudges or particles of dirt or dust that may accidentally be transferred onto unpainted areas of your artwork as you are progressing. Unless removed these may appear as flaws that will show when viewing the artwork from its observation side. If they are also inadvertently covered with a layer of paint removing them afterwards may become very messy and difficult. When lifting off any smudges always be careful not to damage outlines or other areas of paint you have already applied.
Applying the paint
Once the outlines of your subject have thoroughly dried you can begin to apply paint to fill in the remainder of your artwork. Begin with the smallest and most detailed or intricate areas first e.g. eyes, faces, small figures or objects etc – and always keep in mind that your artwork will be observed from the opposite side to the one your painting on and that you are painting in reverse and that therefore foregrounds precede backgrounds.