A method and associated systems for 3D printing on the surface of an acoustic hologram uses an array of sound-wave emitters to generate a three-dimensional acoustic hologram of an object to be printed. This hologram is composed of acoustic standing waves that exert invisible acoustic radiation forces in three-dimensional space that feel like surfaces of a solid object. The resulting hologram creates a tactile illusion of an object floating in space within a three-dimensional printing area. When a 3D-printing medium is applied to the surface of the hologram, the medium solidifies on the hologram's surface to generate a hollow shell in the shape of the object to be printed.