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This section covers everything from how to select a laser marker to the tricks behind clear marking.

Marking vol.1

Q65What type of laser is suitable for marking on metal materials?

KEYENCE offers three types of laser markers.

  • - CO2 laser markers (wavelength: 10.6 μm)
  • - YAG / YVO4 laser markers (wavelength: 1,064 nm)

Since CO2 laser markers cannot mark on metals, YAG or YVO4 laser markers with a wavelength of 1,064 nm are typically used to mark on these types of material.

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Q66Is it possible to read characters marked on a transparent PET bottle?

Yes, there are a number of proven examples of laser marking transparent bottles in the beverage industry. The color of marking is different than a mark produced by an inkjet printer. This is an application that is often used to print the time of manufacturing and the expiration date on the product. KEYENCE also produces a short wavelength C02 laser marker with an absorption rate specifically enhanced for PET materials. This marker allows for enhancement of the coloring characteristics as well as minimization of damage to the surface of the PET bottle.

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With the ML-Z9500 Series:

Three-dimensional objects can be printed easily and freely.
Clear printing is possible even on a high-speed line.

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Q67Is it possible to print on and make perforations in transparent film?

Yes, it is possible. When a transparent film is printed using a laser maker, small pinholes often occur inside the printed characters, which is unavoidable due to the heat of the laser. In such a case, a short wavelength laser is the best choice. Since it can print characters on the surface of a film in white relief without creating pinholes, it may also be used to mark 2D codes. Additionally, when cutting film using a short wavelength laser, the cut will be very precise.

9.3 μm short wavelength laser

For resin products such as PET, PC, etc.

The wavelength of the laser beam is shortened from 10.6 μm to 9.3 μm in accordance with the heat absorption characteristics of the resins.
This allows for printing of shallow engravings with high visibility and less raising of the surface as well as precision cutting. This also guarantees outstanding, high quality markings in the printing and processing of films and sheets.

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Q68What is the depth of my mark?

This question is often asked when using laser markers, yet the depth of a mark can differ greatly depending on the marker type, the parameters, and the material being marked. For example, the depth when marking plastics can be easily controlled and varied from shallow marks (a few microns deep) to cutting films (1 mm or thicker). However, since metal marks are typically only 10 um to 90 um deep, making deeper marks takes significantly more time. Thus, a wide variety of marking styles are available according to the application's requirements by changing the laser power and marking speed.

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Q69What are the biggest and smallest characters I can mark?

Depending on the model and type used, very small clear marking is possible starting from 0.1 mm (0.004") for small characters. However, wider area models allow for marking over a large 300 mm (11.81") area. Because of this, characters can range in size from 0.1 mm (0.004") to 300 mm (11.81").

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Q70Is it possible to mark on ceramics?

Yes, it is possible. Since there are different kinds of ceramics, it is necessary to select the type of laser marker according to the application. For example, the CO2 laser marker is appropriate for alumina ceramics and the YVO4 laser marker for zirconia ceramics. To ensure good consistent marks, it is recommended to test different marker types to see which gives the best type of mark.

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Marking vol.2

Q71What happens when my target moves out of focus?

Laser markers typically provide their best marks when a target is at the focal point. The further a target is from the focal point, the less focused the laser spot is. This means the marking can become faint due to enlarged spots and decreased energy density. Below are some examples of what marks look like when a target moves out of focus.

Marking on steps

Marking on a slope

Marking on a cylinder

Marking on a cone

KEYENCE's range of 3-Axis Laser Markers solves all of the problems above.

Combining a laser displacement sensor allows for in-focus marking as a target moves further or closer to the laser marker.

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Q72Is it possible to mark my company's logo?

Yes, KEYENCE's editing software, Marking Builder 2, allows for the use of various types of graphic data. Among these, DXF files created with CAD software can be easily loaded as logo marks. This makes it possible to quickly mark company logos as desired since it allows for flexible editing such as selecting the style of hatching and laser marking path.

Easy-to-use editing tool, Logo Designer

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Q73Are 2D codes readable when marked on metal targets?

Yes, they are. There are various methods for marking 2D codes on metal targets with a laser marker. For example, black marking is okay on target surfaces such as iron and stainless steel.1 On the other hand, black marks on a matte surfaces cannot be easily read with standard 2D readers. In order to solve this problem, readable 2D codes can be marked by creating a "polished" white background first with the laser and then a black 2D code on top.2

Black Marking

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Q74How difficult is it to mark ●,Poor, and ■ characters?

Simple shapes such as circles, triangles and squares, which are not as complex as logos, can be easily created with Logo/Custom Character Editor in KEYENCE's Marking Builder 2 software. This editing tool allows for quick, easy creation and manipulation of user-defined custom characters and font sets.

Logo/Custom Character Editor

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Q75Is it possible to count or change values when marking serial numbers?

Yes, it is possible with the KEYENCE ML-Z and MD-V range of laser markers
The most common methods are:

  • Counting with a user configured internal counter
  • Sending external serial numbers via serial communication

The internal counter can respond to various cases since it is possible to change the number of steps, repetitions, and base of the count. In addition, it is also possible to reset the counter or count directly from the discrete I/O terminals.
Serial communication allows for configured counters or marking blocks to be changed directly as desired.

Counter settings

Q76How can I ensure that a target will be marked within a given time frame?

The "Scan Speed Optimization" method allows users to automatically calculate the correct scan speed settings to complete marking within a given time frame. This function can be used to calculate scan speeds when marking moving targets as well.

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Marking vol.3

Q77How can I mark characters to represent the time shift in which a part was marked?

This can be done with the "shift code function". A maximum of 24 shifts per day can be replaced with characters.
This enables printing by updating the alphanumeric characters automatically according to the internal clock.

The following is an example of dividing a day into three shifts and replacing them with alphabetical characters.

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Q78How can the marking time be decreased?

In some cases it is possible to simply increase the scan speed in order to decrease marking time, but this can lead to poor quality and faint marking. If this is the case other methods, such as changing the direction of the filled in pattern can be an effective way to decrease marking time.

Example of changing the direction of the fill

It is possible to change the direction of marking inside of a pattern as well as the order in which the patterns are marked to increase efficiency and decrease marking time.

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Q79How can changing the Q-Switch frequency of a YAG/YVO4 laser effect marking quality?

The KEYENCE MD-V9900 series laser markers have a Q-Switch range from 0-400 kHz. A low Q-Switch value allows the laser to build up more power before its release. This is more beneficial for deep marking on metal and for marking at slower speeds. A high Q-Switch value means that the laser is pulsing more frequently and not allowing the laser to build up as much power. This is useful for marking without damaging the surface of a target and for marking at higher speeds. The example below illustrates why marking with a higher Q-Switch is necessary for high speed applications.

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Q80Can marking be accomplished on plated surfaces without removing the surface layer?

It is impossible to perform marking without causing some effect to the surface of a target. However, it is possible to limit the amount of damage to a plated surface by finely adjusting the marking parameters. The example below shows marking on a galvanized metal target where marking depth has been controlled to within 1 μm (0.04 Mil).

It is possible to perform clear, high speed marking even on difficult to mark products that have a high reflection ratio, such as gold plating, by selecting a laser that produces an appropriate wavelength of light.

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Q81Is it possible to vary marking parameters in order to easily find the correct settings?

KEYENCE laser markers are equipped with a “Sample Marking Function” to simplify the process of selecting the correct settings. Even new users can easily find the appropriate settings for difficult marking applications with the click of a button.

This function arbitrarily changes the combination of power, scan speed, Q-Switch frequency and focal distance in a combination of up to 123 patterns. This function decreases the amount of time spent on trying out different combinations of marker settings and reduces the amount of scrap material needed to dial in the right settings for any given target.

Sample marking example

Scanbeat (mm/s)
500 1000 1500 2000 2500 3000
Laser power (%) 20 A0 A5 AA AF AK AP
25 A1 A6 AB AG AL AQ
30 A2 A7 AC AH AM AR
35 A3 A8 AD AI AN AS
40 A4 A9 AE AJ AO AT

Up to 123 pattern combinations can be applied at one time. The alphanumeric labels not only act as a means of selecting the correct pattern, but also represent how single line characters will appear when marked. The boxes next to the alphanumeric labels represent how filled patterns and thick text will appear when marked.

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Q82Is it better to mark slowly when etching metal targets?

Generally speaking, using a slower scan speed tends to create deeper, more legible marks. However, using a scan speed that is too slow can lead to deposits of soot on the surface of the material. Using thick text lines and marking multiple passes usually leads to the best results.

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Marking vol.4

Q83Is it possible to print mirrored text?

KEYENCE's Marking Builder 2 software is equipped with a "Mirror Image" function. To enable this, simply check the option box.


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Q84Is there a way to easily position extremely small targets to be laser marked?

The finder function of the MD-V series is very effective in such situations. The laser marker contains a built-in camera that displays the marking area on a monitor to facilitate accurate positioning. The finder function lets you produce markings in the exact position needed, even on extremely small targets that cannot be accurately positioned using a guide laser. This makes it possible to perform marking quickly and without creating scrap material.

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Q85Will marking e-coated products lead to the formation of rust?

E-coating is often applied to parts in order to prevent rust. Removing this coating should raise the concern that the product is no longer protected. However, many e-coated products marked with CO2 lasers have successfully passed salt spray tests. Before adopting such a system, it is vital to conduct test marking and/or salt spray testing in order to evaluate whether or not laser marking will meet your needs.

Example marking on a coated surface

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Q86Is it possible to mark products that are coated with oil?

If there is only a very thin coating of oil on the surface, it should not be a problem. However, if there is a lot of oil on the surface, the laser beam may not be able to pass through. In such cases, marking may be distorted, stretched, or otherwise defective, so products that have a thick coating of oil need to be pre-processed with compressed air or wiped down to remove oil.

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Q87Does marking on glass cause cracks?

Results depend on the type of glass used. As glass is transparent, it is usually marked by applying heat using a CO2 laser. With heat-resistant varieties like quartz glass, it is possible to produce clear, crack-free marking.
In comparison, applying heat to soda-lime glass causes minute cracks to appear, so it is necessary to make repeated scans using low power settings.


Marker used: CO2 laser marker


Marker used: CO2 laser marker

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Q88Can a laser marker be used to create labels?

Yes, most labels can be pre-printed by applying a layer of ink to the surface, which can then be removed by a CO2 laser. Unlike conventional printing methods, laser markers can be used for in-line serial number management and other applications because they are capable of printing variable information. Compared to other methods of printing such as ink-jet, marks made with laser markers do not fade and are increasingly being adopted across a range of industries. In addition to regular paper labels there are also "laser labels", which are designed for use with laser markers. Laser labels make it possible to print clear, extremely durable labels on demand. Laser labels are becoming increasingly popular in the transportation industry.

Marking GS1 DataBar barcodes?now mandatory in the medical industry

A laser marker can be used with a labeler to provide in-line marking of use-by dates, lot numbers, and other variable information.

Creating a nameplate with a laser label

Label designs can be managed via computer, allowing for easy changeovers of information to be printed.
This significantly reduces lead time as well as man-hours required for inventory management.

Labels can also be cut away from the backing using a CO2 laser, allowing users the ability completely design a label of their choice.

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Marking vol.5

Q89Is it possible to mark characters in a circular layout?

You can easily design a circular layout when creating programs in the “Marking Builder2” editing software or on the MC-P1 touch panel module. Users can either set a predetermined radius or simply click and drag the center of the text until it conforms to a circular reference.

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Q90What is a lasers range of focal depth?

A laser marker provides the highest energy density at the lasers focal point. If the laser beam becomes unfocused, variations in marking and skewed characters can result. Many KEYENCE laser markers have been designed with the added functionality of being able to adjust this focal range by up to 42 mm without moving the target being marked. This allows for KEYENCE lasers to adjust for marking on 3 Dimensional shapes, compensating for height differences or vibration on moving production lines as well as purposely de-focusing the beam to provide for more aesthetically pleasing marks.

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Q91How can I obtain CAD data of laser marker dimensions?

You can download CAD data from the KEYENCE web site.
For 2D-CAD, DXF files are available.
For 3D-CAD, three types of data files (IGES/Parasolid/STEP) are available.

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Q92What benefit does a 9.3 μm wavelength CO2 laser marker provide?

In comparison with the typical 10.6 μm wavelength models, a laser with a 9.3 μm wavelength provides higher absorption into resins, plastics and films, allowing for transparent materials to be marked or cut without generating as much heat and therefore causing less damage to the surface of the target. Because marks generated with a 9.3 μm wavelength laser are shallower in depth, clearly legible marks are more easily created due to more light being reflected and less light being trapped within the depth of the mark.

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Q93Can I use a laser marker for small volume production?

Laser markers can be used in large scale or small volume production. Initial setup and alignment for part marking is identical in both cases. There are a variety of alignment guide lasers to ensure parts will be marked in the correct orientation. KEYENCE lasers can be setup for large and small batch marking and also have the ability to compensate for moving targets.

The versatile guide laser function can simplify visual laser positioning

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