A basic principle of colouring faux stone is that the bigger the job the more colours are needed to prevent an unnatural repetitive look. A small project of say 5 square metres may only require 3 basic colours. However if you only used 3 colours on a 20 square metre job the result would look unreal due to the sameness of the applied colour.
To achieve a natural look using only 3 basic colours , additional colours can be obtained in the same colour range by varying the dilution of the 3 base colours. This can yield dozens of additional shades of colour to achieve what you see in nature.
A different tone of base colour is used depending on the type of rock you are endeavouring to simulate. For instance to replicate the yellow/tan colouring of Sydney sandstone, you might start with orange, yellow and tan as your base colours. Each of therse colours could be mixed with a percentage of a light colour perhaps white or grey say 10% and 30% dilutions to give nine base coat colours in all.
All colours are still in the same family of sandstone colours giving the overall effect of multiple colour shadings of natural sandstone. All colours can be diluted with water to an even greater extent than the 50% dilution they should start with to give subtle tonal colour variations.
For larger jobs adding one extra colour say brown, green or a little black to give a palette of 4 base colours would expand the colour diversity of the project enormously.
Colour base coat application techniques:
Use a cheap spray bottle found in any garden department. The base colours are to be applied to the stones in a random fashion using all base colours after the previous colour application has dried.
Try not to give an even overall colour appearance.
(1) Miss a stone here and there.
(2) Colour the top or bottom of a stone only.
(3) Hit only the top or bottom of a stone with the spray.
(4) Cover part of a stone evenly and then taper off to practically no colour on other sections of the stone.
(5) On 10% of the stones give a two tone effect by spraying 2 colours on the same stone.
Colour top coat application techniques:
Once the stones have been treated to the random application of the base coat colour znd let dry, it is time to apply the top coats.This can take many forms from :
(1) Lightly spraying an off white or light grey diluted 50/50 colour over all the stones. This has the effect of toning down the overall colour of the job.
(2) Use a semi-dry brush from which most of the colour has been removed by wiping on newspaper or cardboard and lightly brushing horizontally across the surface of the stones to leave a slight colour deposit. This dry brushing technique leaves the colour deposited only the raised portions of the stones.
Each of these methods will give a slightly different effect. For some jobs the overall light colour spraying will give the effect required while on others the dry brushing technique will look terrific once it has dried. Do not be disturbed by the appearance of the wet colours. All colours dry lighter in colour. It is a good idea to practice on several pieces of stone to give you an idea of the effects that will be achieved.
Final colour specking:
Small specks of colour can usually be seen on natural stone. This effect can be achieved using a faux brush from which you have exhausted most colour. Flick the brush with your wrist at a sheet of used cardboard until the right size small colour drops can be seen on the surface of the cardboard. Only then commence to flick colour on the stones to give the required coverage. Too much colour on the brush will give big wet drops that look totally unrealistic. Less is more in this case.
Well diluted white, light grey or black colours are used for this final colour application.
The basic techniques described above will give you stone which will be 1000% better than what is commercially available at the present minute. Artificial rock can look dreadful if is not treated correctly to give a natural look. Properly done it is almost impossible to say what stone is real and what is not and this is the standard you should try to achieve.
Additional techniques can be described as stippling, bleeding, dirty brushing. faux brushing, spray painting, spritzing, colour wiping, antiquing and sanding. This final technique involves using a sanding block and sanding back the colour to reveal the grey underlying cement colour. Used with discretion this can bring a job to life. All these methods will be discussed in the coming months to enable the very highest standards to be reached by our customers.