Is the work of a designer who places pictures of adult women on gifts considered a partnership in sin, and is submitting his resignation better to absolve himself, knowing that he dislikes this work and is looking for an alternative?

There is no objection to the aforementioned work if the images of unveiled women are avoided. As for images of unveiled women, it is preferable to avoid them, but if they are displayed, there is no sin unless it is highly probable that they will be presented in an unlawful manner. It is not permissible to deal with images of unveiled women, but there is no harm in remaining in the job while avoiding forbidden images. If another job without doubt is found, that would be preferable.