Basically Hydro dipping is a way of adding a coating to an object with a colour or design. This how Wiki expalins the process
Hydrographics or
HydroGraphics, also known as
immersion printing,
water transfer printing,
water transfer imaging,
cubic printing, or
hydro dipping, is a method of applying
printed designs to three-dimensional objects.
[1] The hydrographic process can be used on metal, plastic, glass, hard woods, and various other materials. In the process, the substrate piece to be printed is pre-treated and a base coat material is applied. A
polyvinyl alcohol film is
gravure-printed with the graphic image to be transferred, and is then floated on the surface of a vat of water.
[2] An activator chemical is sprayed on the film to dissolve it into a liquid and activate a bonding agent. The piece is then lowered into the vat, through the floating ink layer, which wraps around and adheres to it.
[3] After removing the piece from the water, a top coat is applied to protect the design. With multiple dippings, hydrographics printing can achieve full 360° coverage of the part surface, including small crevices