The Meaning of 3D Relief Effect

3D relief effect includes 3D effect and relief effect. Among them, 3D effect is a visual effect; relief effect is a tactile effect. 3D effect is mainly a visual sensory experience. It usually uses image processing software to process the pattern in three dimensions, so that the image appears three-dimensional visually; while relief effect is a real tactile bulge, which is achieved by stacking white ink multiple times through UV printing technology to form an undulating structure on the surface of the material. Then, by superimposing the color pattern and printing, a three-dimensional pattern that is both visible and touchable can be formed.

Imaging Principle of 3D Relief UV Printing

The core of the three-dimensional/embossed effect is to allow the UV ink to form a certain thickness in the designated area of the pattern through repeated printing or continuous ink stacking.

Utilizes the grayscale control of the printhead (variable ink droplets) + multi-channel stacking function.

Layer by layer, UV ink is cured once per layer, and finally a raised structure is achieved.

Commonly used materials are transparent acrylic, metal plates, leather, PVC, PET film and other hard or semi-hard substrates.

Different printing channels can be controlled in different areas to achieve composite effects such as local high, local flat, and local bright.

3D Relief UV Printing Sequence

Taking the standard relief structure as an example, the printing order is usually:

White ink primer (to enhance hiding power)

Color ink pattern printing

Multi-layer varnish stacking (to achieve 3D effect)

Top transparent protection or matte cover (optional)

It is also possible to use varnish alone to stack to achieve transparent relief patterns (such as colorless LOGO embossing, anti-counterfeiting relief, brand texture, etc.)

Notes when printing:

All printed layers need to be UV cured immediately to prevent flow and pattern ghosting;

The varnish layer cannot be too thick at one time. It is recommended to print in layers and cure multiple times.

High temperature or high humidity environment can easily affect the curing effect. It is recommended to control the temperature of the printing room to be stable.

Unstable registration accuracy will cause relief offset, ghosting, and uneven ink accumulation at the edges.

Requirements for 3D Relief UV Printing

Key equipment requirements

Printheads that support grayscale printing: such as Ricoh Gen5, Gen6, Toshiba CE4M, Kyocera.

Precise positioning platform: Multi-layer overprinting requires high positioning accuracy, and the platform must be stable.

High-output UV light source: Each layer of ink must be completely cured to avoid flow and deformation.

Software that supports multi-pass printing: 3D layer information (white image/stereoscopic image/color image layering) needs to be imported.

Image file requirements

3D relief printing must use a layered file structure, the common method is as follows:

Color map (color layer)

Varnish map (bright layer or three-dimensional layer)

White mask (used to enhance the opacity of the underlying layer)

Most software supports using the varnish layer as a transparent channel/black and white map/height map to control the thickness of the print area.

Note: The 3D layer generally uses a gradient black and white image to control the print thickness (black = more ink, white = less ink).

UV ink requirements

Adhesion and finished product stability: the ink needs to have good adhesion to prevent the stack from falling off/curling.

Rheological properties and edge control: the ink should be quickly fixed after being inked and not easy to spread. Excessive fluidity will cause the edge of the layer to expand and the varnish to clump and become blurred.

Curing speed and light response: Printing relief layers usually adopts the method of "printing one layer → curing immediately → printing the next layer". If the ink responds slowly to the UV band, it may cause problems such as the ink stacking height not being able to be increased.

Common Application Scenarios

High-end packaging: LOGO raised, local highlights, brand texture

Phone case decoration: pattern relief, partial glossy + frosted contrast

Cosmetic bottle: colorless relief, three-dimensional texture of brand name

Personalized decorative painting: partial metal feel + three-dimensional superposition

The picture comes from the Internet