After a 3D print finishes in a single color and you want to make it colorful or add some patterns, hydro dipping is a great post-processing technique that can help you to do that.
Not only can the pattern be added on flat surfaces, but it can be freely added on 3D curved surfaces. So it is a good method to be used on 3D printed objects.
What is hydro dipping technology
Hydro dipping, also known as water transfer printing, immersion printing, Hydrographic, water transfer imaging, cubic printing or water marbling, is the process that enables you to transfer a sheet of printed graphics onto the 3D surface of an object.
The Hydro dipping film which contains the printed patterns dissolves in the water and leaves a layer of paint floating on top of the water. When you dip an object into the water, the paint will conform and then stick to the surface.
The Hydro dipping process can be used on glass, metal, hard woods, plastic and a lot of other materials.
For even further information about Water Transfer Printing visit wikipedia here.
Watch water transfer printing technology on Youtube.
What you need before applying Hydro dipping process
- Hydro dipping tanks
It is used to immerse objects in the water, and it should be deep and wide enough. It is best to have the function to control the water temperature. Recommend water temperature: 28~32 ℃
- Hydro dipping film (water printing films)
Water printing film is like paint; a lot of factories can manufacture films. So you can get films on market directly. If there is no image or pattern what you need, you can look for a supplier to help you.
- Hydro dipping Activator
It is sprayed over the film; after activation, the film will become a form of liquid ink, then it will float on top of the water. And it won’t affect the pattern’s structure and appearance.
- Primer
The object must be free of all oils, dirt, grease, loose paint, wax or other contaminants which may affect the finished product. So need to clean the object before applying primer.Then you can apply primer on the object.
- Base Coat
You can spray the object with an appropriate base coat. And the patterns will appear radically different depending on underlying base coat.
- Top Coat
After the object is rinsed with water and dried, you can apply a top coat to protect the object. Usually it is a clear coat. After top coat, need to dry again.
- Respirator Mask
- Gloves & Protective Sleeves
- Scuff Pad
- Blue painters tape
Hydro dipping Kit
On the market, there are many cheap hydrographics kits. It will be convenient for you to apply water transfer printing on 3D objects.
Note: If somethings are not contained in the kit, you can buy them separately, especially the Gloves and Respirator Mask that will protect you.

General process of water transfer printing
Prepare Film —Activation—Clean the object—Apply primer—Apply base coat—Transfer—Film Removal and Rinsing—Drying and Top Coating
There is a simple tutorial on instructables.com.