Glossary · Technology

UV printing

Relief and texture

Many layers printed on top of each other create raised areas that you can feel, for example brush strokes, wood grain or Braille.

Explained in more detail

Because UV ink cures immediately, each layer can build on the previous one. The height is usually created from white ink, varnish or both, with colour and optionally gloss varnish on top. The height is controlled with a greyscale map: depending on the software, light or dark areas receive more layers. Typical heights are fractions of a millimetre; with many passes, a few millimetres are possible depending on the machine. Print time increases with every layer, and the head distance must grow with it, otherwise the head drags across the print.

Where does the term come from?

"Relief" comes via French from the Italian "rilievo" and goes back to the Latin "relevare" = to raise up. In sculpture it means forms worked out of a surface, whereas UV printing builds them up layer by layer.

In practice

• Raise only the areas that should be tactile and leave the background flat; this saves a lot of white, varnish and time.
• Slightly blur the height map before loading it, otherwise noise in the greyscale image turns into small bumps in the relief.
• Manufacturer figures are maximum values (up to 5 mm on the eufyMake E1); for most designs, fractions of a millimetre are enough.
• Vertical edges and thin, tall lines work poorly; wide shapes with soft transitions work better.
• Do not print relief on surfaces that come into contact with food, and for impact or bending loads it is better to work flat with varnish.

Not to be confused

Not every printer with a varnish channel also has a texture mode. Whether relief is possible and what height is given in the manufacturer's specifications.

Frequently asked questions

How high can a UV printer print relief?

That depends on the machine: for tactile spot varnish effects, fractions of a millimetre are enough, and desktop machines with a texture mode quote up to about 5 to 15 mm. The higher it is, the longer the print takes.

Is light or dark high in the height map?

This is determined by the software; often light is high and dark is flat, though some programs work the other way round or let you switch. Check it in the preview before printing.