These leather articles are made by Sonnenleder from Bodman-Ludwigshafen on Lake Constance. Paying painstaking attention to the smallest details, Sonnenleder maintains traditional leather-making practices and stands for consistently functional styles and minimalist designs. The hides of south German cows are vegetable-tanned according to traditional methods and then air-dried.
The tanning agents contain extracts from bark, roots and fruits. In twelve tanning pits with slightly increasing concentrations of tanning liquids, they transform the protein fibres of the cowhides into leather fibres over a period of between six to twelve weeks. After tanning, the hides are air-dried and lubricated in an oil vat according to a well-kept secret recipe. In its pre-dyed state, the finished leather has a characteristic light brown, reddish colour (hence the term "red-tanned"), which looks different in every piece. With use and exposure to the elements, the leather changes colour and develops its own unique patina, which is distinctive of leather. Leather dyed with natural oils and fats in a vat also acquires its own shiny patina over time.

Sonnenleder in Bodman-Ludwigshafen on Lake Constance in the Hegau region stands for consistently purposeful, pure design. The meticulously working company maintains the most traditional method of leather production: pit tanning. Solely hides from southern German cattle find their way into the pits of the company. The tanning agents used by Sonnenleder contain, for the most part, decoctions from bark, roots and fruits. The hides undergo the tanning process in twelve pits with tanning broths slightly rising in concentration; the tanning agents transform the protein fibres of the hides into leather fibres in six to twelve weeks. In the next step, the tanned, then air-dried hides get a fatliquoring finish in a rotating barrel; the composition of the high-quality grease is a well-kept secret recipe. The finished leather thus has a characteristic, slightly light brown-reddish hue (hence the term “red-tanned”), which looks different in each piece. Day-to-day use and exposure to the elements change the shade and result in a patina, a form of natural protection on the surface. Eventually, the leather gains an unmistakable appearance over time. Even the thoroughly imbued leather acquires a shiny patina with use.