The document discusses best practices for laser engraving photos onto different materials. It explains that materials need to hold small dots well to look good, and lists anodized aluminum and laserable plastic as good options. Photos work best in grayscale or black and white. For fine materials that hold dots, like metal, half-toning is best to simulate continuous tone. For coarse materials like wood, error diffusion patterns are better. Good photos are high resolution with no compression. Contrast enhancement and unsharp masking can prepare photos for different materials by increasing or decreasing detail as needed. Converting to black and white with an error diffusion pattern is the final step for coarse materials.

2. Objectives
 What makes a good material
 Diffusion patterns versus line screening
(gray scaling)
 What makes a good photo
 Initial Prep on the Photo – what makes a
good photo
 Contrast Enhancement
 Sharpening the secret to success
 CorelDraw vsPhotoGRAVvs 1 Touch
 Invert
 Vignette
 Cutout Lab in PhotoPaint

3. 6 rules of lasering photo
 Always work in Gray scale (a continuous tone
image) or Black and white this depends on the
material you are going to laser on
 Know your materials that you want to work on
 Make sure that you know your speeds and
powers
 Work only with good photos which shows only
the focus no background images
 Know your adjustment commands
 Crop to Focus

4. What makes a good laserable material

5. When we look at materials there are
three characteristics that we need to
consider

6. 1 The first is how well does the material that we
are working with hold a small well formed laser
dot
2 Secondly how well does that material display
our image. In other word do we see good
contrast. Is there a good difference in colour
between the colour of the lasered and non
lasered area. For example the best contrast is
black and white.
3 The third is how good is the material in terms of
being consistent. Wood is not good because it
has a changing grain, anodized aluminum is
very good because it has no grain

7. Products that hold a dot well are anodized
aluminum, laserable plastic or brass plated steel

8. AlumaMark holds a half decent black dot -
Gold

9. AlumaMark holds a half decent black - Silver

10. Product such as wood do not hold a good small dot
and are very porous. Thus photos do not look as good
on this medium

11. Product such as glass do not hold a good small dot and are
very porous. Thus photos so not look as good on this
medium

12. What this means is that
when we process a photo
we need to establish first
what type of material that
we are going to laser on.
Once we have our material
we can process the image

14. Before we go on let us look at the 3 main
special programs for photo processing
 ULS – One Touch
 PhotoGrav
 PhotoLaser

15. One Touch vs CorelDraw

16. One Touch vs CorelDraw

18. Corel vs One Touch

19. The Ultimate Photo

20. Our Number 1 Rule
Thus materials that hold a good small dot
need to be processed one way while those
materials that do not hold a good dot need
to be processed a different way
Let us look at the two ways we can
process an image.

21. Our two printing methods are:
1- Half Toning
2 -Error Diffusion

22. Our Number 2 Rule
1- Half Toning – Fine Materials
2 -Error Diffusion – Coarse
Materials

23. Halftone and Error Diffusion

24. Half toning - Definition
 Halftone is the reprographic technique that
simulates continuous tone imagery through the
use of dots, varying either in size, in shape or
in spacing. "Halftone" can also be used to
refer specifically to the image that is produced
by this process. Where continuous tone
imagery contains an infinite range of colors or
grays, the halftone process reduces visual
reproductions to a binary image that is printed
with only one color of ink. This binary
reproduction relies on a basic optical illusion
that these tiny halftone dots are blended into
smooth tones by the human eye.

25. Halftone Image – Continuous
Tone Image

26. How Halftone Dots Appear

27. Screen Pattern with a halftone
image

28. Products that typically require
continuous tonal image – Fine
Materials
 Anodized Aluminum
 Black Brass Coated Steel
 Laserable Plastic
 Some Marbles
 Laser It

29. Half Tones which the laser produces
are Better on Anodized Aluminum or
Brass Plated Steel

30. What is Error Diffusion?
 There is a second set of dithering patterns and
these are created using what is called an error
diffusion algorithm. These use a technique of
diffusing quantization error to neighbouring
pixels. Ok let us not get to technical. All you
need to understand is that there are a number
of error diffusion techniques that are available.
Which one that you use is up to you. In
CorelDraw we have 3 error diffusion algorithm
patterns available to us. These are “Floyd-
Steinberg”, “Jarvis” and “Stucki”. Others are
“Burkes”, “Scolorq”, “Sierra”, “Atkinson” and
“Filter Lite”. Figure 2 and 3 shows some of the
more popular patterns that are available to
use.

31. Error Diffusion - Patterns

32. Diffusion Patterns are better on
wood

33. Products that typically require
error diffusion
 Wood
 Thermark Product
 Glass
 Marble / Granite

34. Thermark on a Tile does not hold a good dot
compared to anodized aluminum thus we use an
error diffusion

35. Glass does not hold a good dot compared to anodized
aluminum thus we use an error diffusion

37. The quality of our image can
greatly influence our final product.

38. Thus we need to establish
what is a good photograph
that we can use

39. We need a Good Quality
Image. The worse the image
quality the more chances we
have of not being able to
reproduce the proper image

40. Original Image – Tif No
Compressions

41. Original Image Engraved

42. 100 % Jpeg Quality

44. 100 Percent jpeg

45. 70 % Quality Jpeg

46. 70 % Quality Jpeg

47. Other Bad Photos

48. Low Resolution and to dark

49. Low Resolution and
Background

50. Let Us Take a Close Look

51. Here is the finished photo

52. Best Photos Formats to get
 Tiff or BMP are the best as long as they
are not jpeg’s just saved as this format
 Jpeg is the next best but remember
JPEG can comes in a lot of different
qualities
 You may get a PDF but the original file
may contain bad quality images

54. Converting to Grayscale

55. Working in Gray Scale

56. Image converted to
grayscale

57. Cropping to Size using
PowerClip

58.  Once we have converted the image to
grayscale we will now need to process it
to laser engrave it.
 The Contrast Enhancement Dialogue
box allows us to increase the tonal
range of the photo that we are working
on
 To do this open up the Contrast
Enhancement Dialogue Box

59. It is located in the Bitmap
Menu

60. 3 areas pixel types in our Tonal
Range

61. What is Tonal Range
 When we talk about the tonal range of an image we
are referring to the range of tones between the
lightest and darkest areas of an image. For example,
an image with a wide tonal range will include both
dark and light areas (and a range of tones in
between). Whereas an image with a narrow tonal
range will cover a more restricted range for example
it could be predominantly composed of mid-tones.
Note: when we look at an image that is a grayscale
image we have an image that is comprised of gray
pixels that have a value of 0 to 255. Values that are 0
are solid black and values that are 255 are solid
white. Pixels with a number in between 0 and 255
are a shade of gray.

62. Each slider adjusts certain
pixels

63. Dark Adjustment

64. Light Adjustment

65. Contrast Enhancement

66. Contrast Enhancement box

67. Contrast Enhancement

68. Areas to look for when we are
adjusting

70. Original

71. Minor Adjustment

72. Finished Product

73. Major Adjustment

74. Finished Product

75. Finished Product
Engraved
Dark Medium Lightest
little adjustment medium adjustment Big Adjustment

76. If you are lasering on black brass or
black anodized aluminum you will
need to invert the image so that is is a
negative.

77.  We have worked with photos that would
traditionally be laser engraved on good
material such as laser brass or anodized
aluminum. But what about wood, glass
and granite?
 To engrave this material we use what is
called the error diffusion technique

79. To Successfully Laser Engrave
Porous or Course Material like
Wood and Glass we need to do
an extra adjustment to our
photo
We need use an error diffusion
pattern

80. Different Diffusion Patterns

81. Error Diffusion Pattern created
on Glass

82. How do we create an error
diffusion on our original image

83. Convert our image in
CorelDraw

84. Our photo converted to black and
white with an error diffusion pattern

85. The Holy Grail for
Doing Photos In
CorelDraw

86. Our Original Image

87. First convert the photo to Grayscale

88. Open the Contrast Enhancement Dialogue
Box

89. I have increased the tonal range of the photo
Original Adjusted

90. Now the question as to how much I adjust is
dependent on what I am putting the image on.
If I am going onto metal or plastic I would do a
lighter adjustment as I can show more detail
on this material. If I am going onto wood I
would use a more drastic adjustment

91. So the rule of thumb is more detail in your
image if you are going to go on good material
such as laser brass. This is because I am
going to use the halftone image to print my
photo. Thus I use a smaller adjustment in the
contrast enhancement command
If I am going on a porous product such as
wood I need to get rid of detail. Thus I would
do larger adjustment in the contrast
enhancement command

92. Remember that the worse (the more
porous) the material that we are working
on the more that we have to remove
detail, Thus the better the material the
less detail that we need to remove in the
photo

93. Now the secret step - Unsharp Mask

94. This technique is used all the time in
printing colour photographs because
more photos are digital and they suffer
from some sort of fuzziness. The
Unsharp mask will sharpen up these
photos. I use this technique because it
not only does it sharpens up my image
but it gets rid of some of the detail that I
can not produce. Thus the more detail
that I can not produce the more I use the
Unsharp mask

95. Adjust the Percentage and Radius

96. For laser engraving on metal I
adjust the percentage to around
200. For porous material I use 500
and than adjust the radius to suite.

97. Our Image Sharpened

98. Now if I was going to laser
engrave a fine material I would
now send it to the laser
machine.
If I am going to a porous
material I need to do one extra
step

99. For our porous material we need to convert to Black
and White and use our Error Diffusion command

100. Use the Floyd Steinberg
Pattern

101. Here is your finished image

102. Our Image is ready to be
Lasered

103. Our Photo Lasered on Wood