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.