The Shed – September-October 2019

A CREATIVE

LASER APPROACH

EXPERIMENTS WITH LASER ENGRAVING PROVE

TO INVOLVE A LEARNING CURVE WITH SOME INTERESTING RESULTS

By Enrico Miglino

Photographs: Enrico Miglino

I

n this fourth in our series on laser

cutting and engraving, we explore

some creative alternative uses for

using lasers. Laser cutting is often used

to create control panels, boxes, supports,

and all those mechanical details that are

faster and easier to be cut on a laser than

3D printed or — sometimes with less

precision — by hand.

Laser engraving can be used to

convert a photograph or any other kind

of image to an engraved surface in

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subjects are transformed to engraved

surfaces. The intensity of the grey level

of the original subject, from white (zero

intensity) to black (maximum intensity),

is converted to a corresponding laser

intensity value from 0 to 255. The result

is an embossed image derived from the

original greyscale source.

Digital process

A second method (we saw some simple

examples in the previous issue, No. 85)

converts the image to pure black and

white, a digital process very similar

to the photomechanical conversion of

a greyscale image used in serigraphy

(screen printing) techniques.

This is the image-conversion method

better known as ‘digital posterization’.

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the image to a well-balanced greyscale

image. The next step is the posterization

process which consists of selecting the

black-and-white midpoint value. This

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personal choice. Based on the mid-range

The acrylic colour set and the watercolour paper

used to create the images shown in this article

Laser engraving can

be used to convert a

photograph or any

other kind of image to

an engraved surface