In the tannery, the leather goes through the tanning and dyeing process in batches. Since only a certain amount of leather skins fit into a tanning drum, the appropriate quantities are combined into a batch and go through all the processes together. A lot usually contains 50 - 100 skins. It can therefore be assumed that the leather in each batch is very similar.
In certain leathers, where an exact result is not possible, it is common to have differences from one batch to another. This is also referred to as "batch deviations". Pull up leather or aniline leather are not easy to be produced with a consistent appearance. Depending on the lot, they may differ in the end. Leather traders who have such leathers in their catalogue must explain these deviations clearly to the customer so that this does do not lead to misunderstandings. The best option is to show two substantially different leather samples. The customer can then see and identify the various differences amongst the different batches.
Examination of the colour accuracy of leather with the grey scale.
Often, these deviations lead to the buyer assuming that the quality is not sufficient, especially if deviations occur on a second delivery. For leather specialists, this is understandable. Only experts know how pronounced these differences can be in some leather types, occasionally even within the same batch. In the case of disputes, only qualified auditors can then decide whether the deviation is permissible or not. Various measurement methods are available for measuring colour and differences in brightness.
Only a certain number of hides can always be processed together.
Even car leather of BMW in "black" of the same type of leather is not always 100% identical.
In the following photos, the customers had purchased vintage leather as semi-nubuck or pull-up leather and had either only seen one version as a pattern and had noticed the deviation when the furniture was purchased or when they received furniture parts, which were delivered later.
In such cases, better explanation at the outset with photos or patterns could have helped avoid misunderstandings. Often, this important communication does not take place. Even the tannery should ideally point the leather dealer to the possible variance of the batches. Also, the experienced leather trader would have to point out such differences to his/her customers. Ideally by showing samples that demonstrate the maximum variance.
If a customer wants to buy additional furniture, the furniture dealer should send photos and samples to the manufacturer, so that one remains as close to the customer's leather as possible. If this is not enough, the manufacturer has to send samples to the customer, which he can put on the existing furniture to compare. This is complex and expensive, but still better than a complaint, which is annoying for everyone and also expensive.
Strong deviation of leather on later bought furniture. Even for professionals a strong batch deviation.
Difference of leather pattern in the furniture house to delivered furniture. For leather specialists, still within the allowed range.
Additional bought oiled nubuck mentioning the variation of the look in the online shop. Therefore, still within the scope of permissible batch variances in leather.