Abstract <p>The technological process of liquid stamping—crystallization under pressure—which is one of the promising and aimed at expanding the scope of application of high-strength aluminum alloys such as D16, B95, and others, is considered. Since during liquid stamping in sections with a thickness of more than 40 mm, the defects of gas-shrinkage origin and liquation occur that cannot be eliminated by known methods, it is proposed to use the dependence of change in the volume of crystallizing metal on the pressure value as an approach to solving this problem. It was found that the property of metal hidden from known methods of studying the crystallization process, called in the work the term “compactibility of crystallizing metal,” can be up to 5–6% of the total volume of metal. An original research methodology is proposed, and controlled and managed process parameters are determined that ensure the formation of a structure without defects. Advantages of proposed casting process with the imposition of pressure on the crystallizing metal are shown using the example of production of press molds for casting plastic parts.</p>