Technical Note

Photo-ID with dye sublimation printers
for the 958 Laminated ISO Card
Technical Note
The 958 Laminated ISO Card is fully dye-sublimation printable on both sides of the card. This
note is intended to help you understand the range of features available from printer vendors and
how to get the best printing results when using them with your 958 Laminated ISO Card.
Dye sublimation technology
A wide variety of printers is available which can print directly onto PVC cards. These use a process for full
colour printing known as dye sublimation printing. The process is sometimes called dye diffusion or thermal
transfer. It can be full colour, monochrome or just black.
The printers work by passing a thin ribbon of tape carrying the dye between the card surface and a heated
print head. The heat causes the dye to pass from its solid to its gaseous state (sublimation) and then be
absorbed by the surface of the card. Selectively heating different parts of the head allows an image to be
created. The card is transported past the print head three times for the three primary printing colours and a
fourth time for the black parts of the image.
Protective overlay
Some printers use a fifth pass to apply a thin protective film over the surface while others do this with a
separate heated roller. This prevents "reverse diffusion" whereby the ink can gradually escape from the
card surface. It can also increase durability of the image and resistance to wear in swipe reader slots.
Simple overlays applied by lower cost printers only provide marginal extra protection against scratching
while the thin plastic overlays offered by higher specification printers or separate overlay applicators will
make the image very durable.
Printer options
The range of printers is increasing although most use the same print head and similar ribbons. The
differences are in the packaging, mechanical design, capacity & duty cycle, control firmware and the type
of overlay layer applied. Some printers work much faster than others. Some printers produce better and
more consistent results than others. Some printers can print up to the edges of the card (although this can
increase the frequency of ribbon breakages) while others leave a small border. Options are also available to
print both sides in one operation or to encode mag stripes or smart chips. Ribbons are the main consumable
item; maintenance will include occasional changes of a damaged or worn print head. Bewator Cotag Ltd.
does not supply printers.
Photo-ID
The great attraction of the technology is that it allows software packages to print a badge carrying text and
a person’s picture without the need for lamination or adhesive. This gives an attractive image of photographic
quality and reasonable durability. The great benefit is its high security, as it is embedded in the surface of
the card. Bar codes can also be printed.
Clip slot
A clip slot can be punched or milled in one end and/or one side of the card. The diagram overleaf shows
the recommended positions. If the slot is punched in the wrong side or the wrong end, it cuts the antenna
coil! A slot for a card clip is not punched in the card during manufacture because this disturbs or prevents
printing by the dye sublimation printer.
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How to get the best results
The following tips will help you to get good results with the 958 Laminated ISO Card:
• The maximum thickness of the 958 Card is 0.84 mm. Check that the printer is set up to
accept this thickness.
• Dye sublimation printers are very susceptible to variations in card surface material and quality.
Keep the printer well maintained and cleaned. There is usually a roller or rollers which need
regular cleaning. The optimum printer settings will probably be different for different card
manufacturers and plastic.
• Keep the cards clean and free from dust and static at all times. Only remove them from their
protective packing just before printing. Clean the cards if necessary. As well as spoiling the
print quality, contamination can damage the print head.
• Avoid large areas of continuous colour as these are more easily disturbed by small surface
blemishes or particles of dust. They can also pose special problems for some printers, leading
to a transverse stripe effect.
• Some printers cannot print up to the edge of the card. Leave a border of at least 2mm around
the edge. If you need edge-to-edge printing, check that your printer can do this and is
correctly set up. If your printer ribbon breaks frequently, this could be the cause.
• There is a small surface irregularity in the 958 card around the area of the silicon chip
assembly which will make printing over this area very unreliable. Do not print over a square
of 15mm in the top right corner of the front of the card. (Or top left of the back.)
• Correct set-up and adjustment of printer settings will make a big improvement in the results
obtained. Adjustment of the printer contrast in particular has a marked effect on image quality.
• Don’t forget to order enough spare cards for trial runs while you set up your printer.
Cotag International does not accept any responsibility for card loss caused by poor printing.
Chip, coil and slot punching positions
3.2
mm
14.0
mm
Sample card design
20.0
mm
4.8 mm
Logo
Do not print
in this area
15 X 15mm
14.0
mm
Ink jet printed batch
code and reference
number on other
(hidden) side
Cardholder
Name
36.0 mm
4.8 mm
Fixed text message to
suit user requirements
TN124 Iss 1
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Bewator Cotag Limited, Mercers Row, Cambridge CB5 8EX, England
Tel: +44 (0)1223 321535 Fax: +44 (0)1223 366799 Email: [email protected] www: cotag.com