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 stands for a consistently functional, pure design. The meticulously working company still uses the traditional method of leather production: vegetable pit tanning. Only hides from southern German cattle are used for this. The tanning agents used contain mainly decoctions of bark, roots and fruit. In twelve pits with slightly increasing concentrations of tanning broth, they convert the protein fibers of the cattle hides into leather fibers over a period of six to twelve weeks.
After tanning, the hides are air-dried and greased in a lubrication barrel according to a well-guarded recipe. Undyed, the finished leather has a characteristic, slightly light brown-reddish hue, which also gave the leather the name "red-tanned" and which varies from batch to batch. Use, sun and rain change the color tone, and over time a natural protection forms, the patina, which gives the leather an unmistakable appearance. The leather dyed in the barrel also acquires a shiny patina with use.