"When the years have gone by and everything is gone, only the smell in the air remains to keep the past alive." It is often impossible to remember the details of what happened decades ago, but there is always a clear recollection of the smells that permeated the situation at that time, and it seems that you can re-feel the emotions and feelings of that time when you smelled it.Leather smells, and it seems that it should smell good. Some fine brands, for example, like to use leather as an aftertone in their perfumes. Leather could indeed be fragrant, when the old European tanners used only lime, vegetable tannins and olive oil. The development of technological applications has brought efficiency, convenience and reliable physical properties to the leather industry, but it has also brought odours, of the bad kind. Certain types of leather are very prone to odour problems and disturbances due to specific stylistic needs and closed use scenarios, such as furniture leather. Furniture leather often needs a soft, full, moist and comfortable feel, which is best achieved with natural oils and fatliquours. However, natural oils and fatliquors tend to produce annoying odours. The main factors influencing odour problems are shown below: