The Filter

by Mig Jemenze

There are some techniques that would not work alone, by itself, In other words, they can not be used as a final result because or they do not complete any acceptable finish or they do not represent any complete finish concretely. That is what happens with the filter. if done alone, the rest of the project as a whole would still be incomplete The filter is technically a complement - just another brick- that is used with other primary techniques as one more step in that complex painting construction making a final result. But as a brick that it is, we do not have to forget that some buildings are made of stone, cement or wood and therefore the filter brick is unneeded.

What is it?

Around 1992, there was a need to classify a paint effect that modelers didn't always understand and even today is usually confused with washes or rain marks. The filter had the purpose to give a most real aspect to a surface, to help enrich it and to give it depth, working in such way that a completely flat colour base acquired realism with the simple application of the filters. In addition, filters modify the original paint tone of the model with high precision, achieving colors that would be almost impossible to obtain by simply mixing paints.

What does it symbolise?

The textures, the objects, the matherials have, by itself, some own characteristics, independient to the environmental effects, that normally are unnoticed by most modellers as many times is tended to represent only the weathering effects instead the original texture. In example, a metallic painted surface is not shown to our human eye just like a plastic painted surface. The resulting texture, to the margin of the mud, oxides, dirts, etc. is clearly different to each other. The filter, most concretely, tends to represent that small difference of texture and chromatic wealth, in a very subtle way, that will cause that a metal surface looks closer a real a metal surface and not a wooden one.

Also we can understand it as a simple colour filter, as those which are used in photograph to modify the general tone without modifying the contrast or the shine.

How is it made?

A filter is very simple to execute, but first one needs to have a good understanding of the correct materials and tools to use. Most important, one must be able to identify the proper circumstances to use filters and which surfaces should have filters applied.

a) Over a matt surface, the filter will dry quickly and perform with 100% effectiveness. On a matt surface one must note that after the first filter, you will not be able to alter the base color any further with additional ones. In this case it is more useful to make only one or two filters.

b) Satin surfaces are ideal for filters. They are perfect because the filter will dry rather fast and numerous layers of different colors can be applied until the desired effect can be achieved. Satin surfaces will also give a metallic texture to the filters as it does the base color. A maximum limit of 10 or 12 filters will be viable using 4 different colours.

c) Only the glossy surface puts our limit to the edge as the filter may become into a wash, because the filter will not cover by equal the surface due to its shine and it will tend to be accumulated in grooves and seams, in the same way of washes. The drying time will be very slow and hard to control. You will need to monitor the surface until the filter dries. On these brillant surfaces only one or two filters will be useful. More filters may dirt our surface and destroy the desired effect.

In order to make a filter, we must apply a diluted layer of color. The color must be diluted with 95 to 98% thinner and 5% to 2% paint. With this ratio of thinner to paint, we will effectively be able to apply our filter. After the first filter is applied then dries, the surface will appear almost as nothing has been done. One way to see the difference obtained by the filter will be to leave a part of the model untouched. When the filter is dry, compare the untouched surface to where the filter has been applied. Filters should be applied with a smooth, round, number #6 or #8 brush. You can use Humbrol paints for filters and even oils if you want to give vividness to the surface. Pure turpentine spirit can be used as thinner but never use hard thinners or dissolvent because it will eat the base paint. The essences of turpentine are excellent if we are familiar with using them and we are aware of the results. For beginners, I recommend a normal turpentine spirit which are sold in drugstores and supermarkets. Petroleum essence will probably leave fewer marks, but with the time we will see how those filter irregularities are interesting too.

First, dip the brush into the container containing the transparent mixture of 5% paint and 95% of turpentine spirit. Lightly wipe the brush on the side of the container leaving it damp but NOT SOAKED, then immediately apply it onto the surface of the scale model. Brush so that the mixture extends uniformly. It should take about 30 or 45 seconds to apply a filter to a 1/35 scale Sherman and about 10 seconds to the same AFV in 1/72. This is important because we want the drying to be uniform.

We would have a beer, to take a break playing out most addictive computer game or surf the web looking for scale models until the filter is completely dried (1 or 2 hours), before apply the following

We can combine different colorus, ligther or darker, shades of blue, green, or orange colors. The original hue of our vehicle will not change, but as we apply our shades, they will give a surprising result, modifying the vehicle to our desired color with much precision.

Tricks

It is almost impossible to end up with an undesired effect because the filters that we apply are in such light shades. Choosing the turpentine spirit is what you usually should be careful of. I recommend that you buy at least two or more different brands of turpentine spirit and test them on some trial pieces of painted plastic or a couple of old models. Once you have decided on which turpentine spirit gives the best results you will be able to use the bottle on the next 30 models that you build.

Around three years ago I purchased two 500ml bottles of turpentine spirit. The first one never fully dried leaving me with a sticky film on my test model but the second one, however, gave me the best results. Unfortunately I am unable to remember the manufacturer and the supermarket where I purchased the second brand. Now I will need to find another commercial brand of turpentine spirit that gives me the same results to replace the one I am using now.

Use it to...

Filters are used to enrich very monotone and uniform surfaces, to satin excessively matt colours or to modify also colours that are very difficult to obtain using mixtures. Suppose that you want to make a sand colored vehicle that has a slight greenish tint. We can apply our basic sand colors and then let it dry. After the sand color has dried we can add green filters and create our sand colour with the desired greenish tint.

Be aware!!

We must be careful. If we mix a filter that exceeds that delicate ratio of 5% color or if we don't brush the excess mixture off the brush onto the container, we will end up with a result that resembles that of a wash and the Know How Series #3 about the washes would have no sense !!.

The filter is a fundamental step for most of the scale models I do. The filter is an important part of our weathering process and it plays about a 5% role in the total modeling process. Before finishing I would like to say that I'm debating on possibly changing the name of the filter to the "5% technique". We hope that it will create less confusion between filters and washes.

MIG - 2001