Oiled finish means that leather won’t be dyed, but oiled and waxed. This is the most natural finish for leather goods. These items – with oiled finish – are the ones that allow you to observe the magic of vegetable tanned leather most clearly. How fast or how much does the color and surface of the leather change can’t be predicted, as it depends on the usage, environment and care.
The changes in color happen because of the tannins left into the leather during tanning process. These react in time with environmental elements and the first results could be observed quite soon. Even in our nordic climate (in Estonia) few hours of summer sunshine could give visible difference.
Changes in tone could be also quite well notable when I use lighter dyes for leather. For example yellow turns in time to really nice and interesting light brown (at first).