Is my husband's previous earning unlawful if he used pictures of women in swimsuits in his work, and what should he do to purify his money if he used part of this earning to establish his current office, knowing that he is almost certain he did not do so?

Working in the graphic design profession is originally permissible, provided that Islamic legal guidelines are adhered to. These include not using images of immodestly dressed or nude women in advertisements, and avoiding deception, forgery, or fraud. If the worker previously used forbidden images out of ignorance, he must repent. The money he earned from that work is not subject to prohibition, and he is allowed to benefit from it.