Colour and design choices for specifiers
February 1st 2008

Cleaning Research International's Dr Eric Brown considers the choice of colour and design as a preventative maintenance option

Everyone knows that a light coloured carpet will show soiling quickly. Some people know that a dark coloured carpet will also show soiling to a significant extent. In fact the best colour for a carpet is 'dirt' colour.

(Except I was once asked by a lady who was responsible for cleaning the carpets in a nursing home if she could have a urine coloured carpet!).

In fact there are two different ways to describe soiling. There is real soiling.And there is apparent soiling.The term real soiling is used to describe the total soil that is present in the floor covering; most of it is not visible.

Apparent soiling is synonymous with visible soiling; soil that is easily observed by the naked eye.

In experiments I conducted some years ago I have measured as much as 2.5 kg of soil per square metre in a department store carpet. In other words there was more soil than carpet on the floor! Yet the carpet did not look dirty.The reason for this is that a colour had been chosen that closely matched the colour of the indigenous soil.Usually this is all that matters.The soil trapped in the lower parts of the pile is not important.

It has been said that this trapped soil causes premature wear if not removed regularly, but one might argue a little mischievously, that if you fill a carpet to the top with soil it will never wear out! I remember being told by an engineering vice president at the Hoover Corporation in the United States some years ago that they had once conducted an experiment in which they had seeded a carpet with ground glass. The idea was to show that of two carpets laid on the floor of their factory, one seeded with glass and one without, the one with the glass would wear out more quickly. The next part of their experiment intended to show that if a carpet seeded with glass was vacuumed every day with one of their machines, they could extend the life of that carpet. In fact they discovered that the carpet containing the glass wore out no more quickly than the one which did not have any glass in the pile. This bears out the view that our primary concern should be with appearance management rather than soil removal.

The relationship between soil and colour has been studied over many years. Back in the fifties Mann and Morton reported that vivid colours are particularly susceptible to visible change in the presence of dirt. So while we might expect the yellows to disappear beneath a layer of dirt, customers are somewhat more surprised to see colours which are considered to be darker do so too. I have recent personal experience of a casino carpet in a rich red colour which appeared to fade in a very short time.A cleaning trial demonstrated however that the red was simply losing its vividness.

Remember too that if you have a generally dark coloured carpet with pastel highlights, the highlights may well disappear as the carpet gets dirty. I remember a hotel in Barcelona that installed a grey carpet with pink, lemon and light blue highlights in their pre-function area. Within three months the carpet looked grey all over.

If you are contemplating covering a large area and have several designs to choose from you would be well advised to carry out some soiling trials and examine the patterns once they have got dirty.At Cleaning Research International we have a laboratory soiling machine for this purpose. It has been successfully used to advise a high street bank which of six possible designs they should install in their branches. The first choice of design was ultimately rejected because, when dirty it changed completely in appearance. The second choice stood up well to soiling and was the one ultimately chosen.

cri@cleaningresearch.co.uk

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