This lengthy report concerns the advanced method of chemical preparation of paleontological and cultural history objects. Subjects covered are as follows: acids, their characteristics and uses; plastics used in acid preparation methods; and techniques. Acetic acid preparation in its variations has proved to be the solution to tasks formerly classified as hopeless. The essential limitation is found in the fact that at worst the wrong choice of this preparation method leaves no opportunity for reconsideration. Administered with common sense, this form of chemical preparation is, when combined with the appropriate technique, a method to be recommended for the area of activity of many conservation laboratories.