SUMMUM Online Shop. This is what SUMMUM stands for: Amsterdam sobriety with international allure; SUMMUM has secured a firm position in the European fashion market. They have a big heart for fashion. Since 1998, they have been creating widely varied collections that women can experiment with and vary in their own style. They are passionate about designing clothes in which the women who wear them feel beautiful and look their best. At SUMMUM they also have a heart for the people who make the clothes, for animals and for the earth. After all, the way they produce the clothing also has an impact on them.