The Etching Process

Rembrandt, Picasso, Goya, and other masters, used etching to express their artistic vision. This historical art form is used by printmakers today. The etcher uses not only her artistic talent, but also must balance the delicate chemistry involved in developing the image on the plate.

The traditional etching method is unique in that it allows the artist to produce a limited number of almost identical images. Sculptors have a similar process, using one mold and casting it multiple times. Etchings are not simply reproductions, however, as the artist is involved in every step of the printmaking process: drawing, etching the plate, pulling each print, hand-coloring the etching, and finally numbering the edition. Thus, each etching is an original work of art.

The etching process begins in the artist’s imagination, expressed as a drawing. The artist then uses a copper or zinc plate, coated with an acid resistant wax. Her drawing is scratched on the surface of the plate, cutting through the wax, and exposing the metal beneath.

This plate is then immersed into an acid bath. The wax protects most of the plate from the effects of the acid. However, the acid bites away at the bare metal, ‘etching’ or producing grooves in, the surface of the plate. Variations in shading are determined by the length of time that portion of the plate remains in the acid bath. For a single line, the deeper the line the more ink it will hold, and, the darker it will print.

When the acid process is complete, the wax is removed and the plate coated, by hand, with an etching ink. The ink is carefully wiped off the plate surface, leaving the bitten lines full of ink. This wiping determines the appearance of the background of the finished etching. The inking process is repeated for each print in the edition.

Next, a dampened piece of acid-free paper is placed over the etched and inked plate. The plate and paper are then run, by hand, through a flatbed press under very heavy pressure. This process forces the paper into the recesses of the plate, picking up the ink, resulting in a reversed, but exact reproduction of the plate. This reproduction is called an intaglio etching.

Some etchings are composed of only this inked print. Some artists use multiple plates to produce colored etchings. Other etchings are finished with a variety of media. Once the etching is dry, the artist can embellish the etching using watercolors, pastels, etc.

One of the factors that make etchings more valuable is the fact that the plate will wear down with use. Therefore, hand-pulled etchings are limited to a certain number of impressions for each edition. This maintains the highest intaglio print quality, as well as giving the artwork enduring value.

Each etching is then signed and numbered by the artist. This numbering tells the art owner both, the total number of etchings in the edition, and, the number of this particular etching in that edition. For example, an etching might read 24/70, meaning that this is the 24th impression in the edition of 70. Many artists designate a small portion of the edition to Artist Proofs, or AP’s. Artist Proofs are the impressions used to ensure the quality of the numbered pieces.

Today's fine art printmaker can choose from several methods to produce an etching plate. Many artists are now using an alternative method to create an etching plate without the use of acids and toxic chemicals. The process of solar etching has evolved using an aluminum plate covered with a layer of photo emulsion. The plate is created by placing a transparency made from the original drawing over the UV sensitive surface, exposing it to the sun, and then developing it in water. Once the plate is created, the steps of inking, wiping, hand-pulling and hand-coloring the etching is the same as in the traditional method described above.

Etching is a unique art form providing the collector with a beautiful, original work of art.

© 2006 Melanie Fain - All Rights Reserved Worldwide.

Melanie Fain is an artist and naturalist, famous for her beautiful watercolors and hand-pulled etchings. Melanie loves to bring the natural world to her collectors and specializes in birds, insects, and botanicals. Melanie's art has been exhibited throughout the United States in select exhibitions and art shows. Visit Melanie Fain's website to view and purchase her etchings and watrcolors: http://MelanieFain.com/

Laser Marking and Laser Etching on Glass for Industrial Applications

The marking of glass for industrial use has been done for hundreds of years. In the past the methods used have included ink stamp marking, sand blasting, air grit, acid etching, scribing etc.

Industrial applications of glass marking include:

1. Marking of safety information on safety glass used in commercial and residential construction. This includes glass areas around doors and/or entrance and exit locations.

2. Marking of glass for commercial and residential construction to identify the glass or door manufacturer [for product identification and marketing/sales activity]

3. Marking of headlamp or tail light lens in automotive applications for manufactures name, year of manufacture and/or part number. Also used in the manufacture of televisions for marking mirrors and lens.

4. Marking of serial number, product identification, or other manufacturing information for the prevention of theft and validation of warranty claims

5. Marking serial numbers, part numbers, text, or bar codes allowing for parts to be tracked though the production process until final assembly and shipment

The traditional methods of glass marking all involve contact with the surface of the glass product which exposes the product to stress and potential damage. Co2 lasers offer significant advantages for marking glass products. The RF excited sealed beam Co2 laser coupled with a galvo head and software offers the fastest, cleanest, most reliable method for marking and etching glass.

A Co2 laser can laser mark glass with bar codes, especially 2-D or data matrix bar codes, which can easily be coupled with vision systems for reading the data contained in the bar code. The use of bar codes on glass allows for the product to be tracked all the way through the production process until final assembly. This helps assure a continuous uninterrupted supply of product. The laser marked or laser etched bar code can also be used after the sale of the product for identification purposes and validation. This helps to eliminate warranty costs related to counterfeit or unauthorized products.

A Co2 laser marked or laser etched bar code can also be read by vision systems in the manufacturing process to determine the identity of the part. Examples include prescription strength of eye glass lens, or the type of front headlamp lens used in a Honda Civic. This ensures that the part is sorted and used properly throughout the manufacturing process and that the correct number of parts is produced based on anticipated sales for final assembled components.

The advances of Co2 laser marking of glass over traditional methods are extensive. These include:

• No contact with the part as in scribing methods thereby reducing the possibility of breakage to and damage of the part, as well as elimination of the maintenance required for the scribe unit

• No solvents, thinning, or cleaning agents to purchase and keep in stock as in the case of ink marking or ink printing systems, thereby significantly reducing costs of operation and eliminating the need for continuous maintenance associated with these various ink printing technologies

• No pads for ink printing to maintain as they can fall to an angle or become turned sideways causing the printed image on the glass to appear sideways or not square

• No need to stop the glass in place and make sure a secure fit with the rubber mask is formed as in the case of Airgrit marking

• With Co2 laser marking for industrial glass applications the product can be marked on the fly [while moving]. If stopped or 'squared' for marking, five to eight lines of text plus logo's can be laser etched in less than 0.5 of a second

• With Co2 laser marking no supplies are necessary and no secondary process exists for cleaning or maintenance

• With Co2 laser marking changes to the mark [different text, different logo, difference shape, etc] can be accomplished with a simple click and drag command of the mouse

Co2 laser marking for glass in industrial applications is the fastest, most effective, least costly method in which to mark the product.

Jim Morin writes for Worldwide Laser Service Corporation a company that specializes in T.E.A. Co2 lasers. For more information visit http://www.wlsc.com

Understanding Laser Marking and Laser Etching Systems

Laser marking and laser etching are becoming more and more important in a growing number of industries. The basic reasons to laser marking or laser etch your products include:

• The mark is extremely durable, permanent and in most cases cannot be removed without destroying the product itself, this is true for laser marking, laser etching, or laser annealing.

• The laser marking process is accurate, 100% repeatable, fast, with very clear sharp results.

• The laser mark or laser etch can quickly and easily be changed without any machine change over, and, without replacing any tools. The changing of a laser marking or laser etch is a simple drag and click computer operation.

• The laser requires no consumables and no additional purchases of added materials or supplies. Therefore the operating and maintenance costs of owning and running the laser marking or laser etching system are virtually non existent.

Laser Basics

The word laser is an acronym for light amplification by simulated emission of radiation. The laser beam is formed in a sealed tube with an electrode set, laser gas, and electrical discharge. The beam is emitted into a telescope which expands the laser beam from a size of approximately 2mm as the beam exits the laser tube up to 7mm to 14 mm for most laser marking or laser etching operations. The expanded beam is directed into a laser head containing two mirrors located on high speed galvo motors. The laser beam is directed off the mirrors though a single element flat field lens to the product being laser marked or etched.

Typically the laser marking or laser etching fields created range in size from 65mm x 65mm [2.5” x 2.5”] at the smallest size to 356mm x 356mm [14.0” x14.0”] square at the largest. The next consideration is the laser beam spot size. This is the size of the focused laser light energy at the laser marking or laser etching point on the product and can vary from approximately 200 micron [micrometers] or .0078” at the smallest to approximately 540 microns or .021” for Co2 lasers. The laser beam spot size ranges from approximately 20 microns or .0007” at the smallest to approximately 70 microns or .0027” at the largest for Nd:YAG lasers. These small spot sizes and highly focused laser light energy create the detailed, clear, permanent marking that is typical of the laser marking or laser etching process.

Controlling Lasers and Laser Marking Options

Laser markers and laser etchers are controlled via software. Several variables need to be controlled:

1. Laser power as measured in watts

2. Frequency, meaning the pulse frequency of the laser beam

3. Inches per second, meaning the speed that the beam steering mirrors are moving

Determining the correct setting for the laser is the single most important and critical element in the success or failure of the laser marking process. Once the proper settings have been determined and demonstrated a 100% repeatable laser mark can be achieved.

Laser controller software is accessed via a PCI interface card. This sends the digital signals of the computer based marking or etching files to the motors and directs the laser beam to the product being laser marked or laser etched.

There are several different types of laser marking and laser etching and several different considerations in terms of visual results for the laser mark or laser etch.

1. Laser etching produces a visible etching or depression into the material. Laser etching replaces traditional process like mechanical press or pin scribing. Laser etching can be done with either a Co2 or YAG laser on virtually any material surface and to any depth from very light etching to very deep etching. For example, laser etching is used to engrave serial numbers into metal gun frames. Generally speaking with laser etching the material being laser etched is vaporized at the laser etching point due to the typically high power densities of the laser beam at the point of laser etching.

2. Laser marking produces a surface mark with very little engraving and very little disruption of the material surface. This is especially useful in certain industries such as discrete electric components, semi-conductor, electrical fuse, and ceramics where laser etching can actually damage part or change the conductive qualities of the part. Generally in order to produce the laser mark without deep engraving a high speed per inch setting for the galvo head is used.

3. Laser etching and laser marking generally do not produce any color changes and create a colorless impression. There are exceptions as certain plastics will sometimes react to and change color under either Co2 or YAG laser light. Also, in some cases, additives can be incorporate into the materials being laser marked or laser etched in order to produce a color change. Another exception occurs when the wavelength of either the Co2 or YAG laser is changed from those typically used in laser etching and laser marking. This can produce a color change after laser etching on some materials.

4. Laser annealing is another popular form of laser marking. This type of laser marking is generally undertaken with a YAG laser on metal surfaces using lower power, high frequency and slow writing speeds to produce heat on the surface of the product. Laser annealing can be used to replace electro chemical etching and ink marking as the laser annealing process creates a black mark with no etching. Care must be used, as the heat generated can cause iron in some metals to be pulled to the surface, and rust can result if the parts are subjected to sterilization after laser annealing. This can be an especially difficult issue for medical devices

5. Laser ablation is also a popular use for laser marking systems. In this case the laser is used to remove a layer of paint, anodized or some other material covering the surface of the part. For example this process is used to create bear metal contact points on a painted part, to allow battery connection as in cell phones, or to remove paint for identification of parts and manufacturer details.

Jim Morin writes for Worldwide Laser a company that specializes in Co2 and YAG marking systems used in a wide range of applications. For more information visit http://www.wlsc.com

Advantages and Disadvantages of Etching with Beam-Steered Laser

This year, over one-third of all material processing lasers will be installed for product or package marking applications. Since their introduction in the early-1970's, laser markers have evolved as an effective tool for manufacturers who require a combination of speed, permanence, and image flexibility not available from more traditional marking technologies.

Two marking system designs have emerged with notably different strengths and weaknesses. Careful consideration of these laser and imaging optics combinations can provide the optimum tool for a wide range of marking requirements. Process Fundamentals

Laser marking is a thermal process that employs a high-intensity beam of focused laser light to create a contrasting mark. The laser beam increases the surface temperature to induce either a color change in the material and/or displace material by vaporization to engrave the surface. Both marking system configurations utilize this principle of surface modification but differ in the method used to project the laser beam and create the marking image.

The beam-steered laser marker provides the greatest degree of image manipulation. To create the marking image, two beam-steering mirrors mounted on high-speed, computer-controlled galvanometers direct the laser beam across the target surface. Each galvanometer provides one axis of beam motion in the marking field. The beam projects through a multi-element, flat-field lens assembly after reflecting off the final steering mirror. The lens assembly focuses the laser light to achieve the highest power density possible on the work surface while maintaining the focused spot travel on a flat plane. The laser output is gated between marking strokes. This design offers the user the advantages of a computer generated marking image and utilization of the entire laser output for the highest marking power possible.

The mask or "stencil" marking system sacrifices image quality and versatility for significantly increased marking speed. The marking image is created by enlarging the laser beam, projecting it through a copper stencil of the desired image, and refocusing the beam on the target surface to "burn" the image into the material. A single pulse of the laser creates the entire image. If the alphanumeric characters must be altered part-to-part, (i.e., serialization, etc.), computer-controlled rotary stencil wheels index the characters. This technique is aesthetically limiting in that images exhibit a "stencil" appearance with breaks in the marking lines. Since the mask blocks a high percentage of the laser beam, marking power and resultant surface penetration is limited. Laser and Imaging Combinations

Beam-steered Nd:YAG

The combination of the Nd:YAG (Neodymium:Yttrium Aluminum Garnet) laser and the beam-steered delivery optics marks the widest range of materials and provides the versatility of computer controlled image generation.

Nd:YAG lasers amplify light in the near-infrared at 1.06 mm. Metallic materials absorb a comparatively high percentage of the light in this region of the spectrum. In the pulsed mode, the Nd:YAG laser produces peak powers considerably higher than the normal continuous-wave output. A 90 watt CW Nd:YAG laser, pulsed at 1 kHz, will emit a train of pulses with peak powers of 110,000 watts. The Nd:YAG lasers ability to emulate an "optical capacitor" provides the power necessary to vaporize metallics and other materials. The high peak power will vaporize material up to 0.005 inches deep in a single pass or greater with multiple passes. The non-metallic materials normally associated with the far-infrared wavelength of the CO2 laser are usually highly reflective to the Nd:YAG. However, the high peak power of the Nd:YAG can often overcome the higher reflectivity. Some overlap does occur among many plastics that absorb both wavelengths equally well.

The beam-steered marker can duplicate virtually any vector graphic image including variable line widths and images as small as 0.010 inch or less. In addition, the computer can instantly change any graphic element or the entire marking program before a new part is positioned for marking. The Nd:YAG laser offers a greater range of adjustable process variables to achieve a specific material modification but at a correspondingly higher purchase price than the CO2 laser.

Beam-steered CO2

The continuous-wave CO2 laser can also be combined with the beam-steered delivery system. CO2 lasers emit a narrow bandwidth of light in the far infrared at 10.6 mm. This wavelength is most suitable for organic materials such as paper and other wood products, many plastics, removing thin layers of ink or paint from a substrate, and for marking ceramics. It does not produce high peak powers when pulsed.

Typically utilizing laser powers up to 50 watts, these systems combine the far infrared wavelength with the image control and flexibility of beam-steered image generation. Typical uses include serialization of ceramic and plastic products that require high-quality graphics such as company logos and/or significant amounts of additional alphanumeric text. The lower power CO2 marker does not provide the power to "engrave" substrates but, due to the comparative simplicity of design, can be purchased at a lower cost than the beam-steered Nd:YAG marker.

Mask CO2

Applications that require high speed but not high power and do not vary the marking image except for alphanumeric text (i.e., serialization, date code, etc.) utilize the mask CO2 marker. The CO2 laser is pulsed at rates of up to 1,200 pulses per minute. The high repetition rate provides marking of parts "on-the-fly" at high part-transfer speeds. Computer controlled masks can alter up to three lines of text at speeds of up to 720 parts per minute if the alphanumeric code must be changed.

Advantages and Disadvantages

Beam-steered Nd:YAG

The beam-steered Nd:YAG provides more marking power and far superior imaging than any other laser marker configuration. The available high peak power can mark or engrave a wide variety of materials including hardened metallics. Present computer technology produces highly intricate graphics with linewidths and accuracy's of less than 0.001 inch. Because “drawing” with the laser beam creates the image, the marking time is dependent on the amount of text and the complexity of any graphics. The Nd:YAG laser marker is the most costly of the three system configurations. The beam-steered Nd:YAG marker frequently replaces acid and electro-etch systems, stamping and punching systems, and those other marking systems which permanently mark products by imprinting or engraving. It also replaces ink jet and other color printing systems. Typical applications include marking pistons, bearings, valves, gears, and a multitude of other components in the automotive industry; heart pacemakers, replacement hip joints, and surgical tools in the medical industry; computer chassis, disk drives, and integrated circuits in the electronics industry; tool holders, drill bits, and cutting tools in the tool industry; and writing pens, nameplates, and golf club grips.

Beam-steered CO2

The acquisition and operating costs of the beam-steered CO2 marker are lower than the Nd:YAG marker due to the relative simplicity of the laser. Image generation is equal to that of the other beam-steered system while speed and depth of penetration are considerable lower due to the lower power of the CO2 laser. Although not as popular as the beam-steered Nd:YAG and mask CO2 markers, the beam-steered CO2 system is frequently used for marking general plastics and plastic and ceramic connectors and packages within the electronics industry.

Mask CO2

Although the mask CO2 does not offer the imaging capabilities of the beam-steered design, it is far superior in speed. Because a single pulse of the laser creates the entire image, throughput is typically limited only by the pulse rate of the laser and the transfer speed of the parts handling system. While the part must be stationary while marking with the beam-steered design, parts are marked in motion with mask systems. Depth of penetration is less than the beam-steered CO2 marker since the laser output is spread over a large area with correspondingly low power density.

Masked CO2 markers most frequently compete with ink-jet marking. The mask CO2 laser is often the marker of choice for sequenced coding, batch coding, open or closed date coding, and real-time coding of paper or cardboard, ink or paint coatings, glass, plastics, coated metals, and ceramics.

While the beam-steered design provides superior imaging and material penetration and the mask design provides superior speed, either system provides a better combination of speed, permanence, and imaging flexibility than other marking techniques. Many users also benefit from the non-contact nature of laser marking and the elimination of additive materials such as inks or paints.

The development of a successful marking application requires careful consideration of the laser output characteristics, the design of the optical beam delivery and image generation system, the properties of the target material, and the aesthetic and physical properties of the desired mark. Industrial laser marking systems provide prospective users with several system designs from which to choose to match the optimum marking performance with the users unique requirements.

Richard Stevenson is the Sales Director for Control Micro Systems, Inc. a manufacturer of beam-steered laser marking systems. He has published and presented numerous technical papers and articles on laser marking in trade publications. For information on Laser Etching, Welding, Engraving, Cutting, Etching or Marking call 407-679-9716 or email sales@cmslaser.com

Digital Camera LED Laser Etching Trick

It’s a common scene no matter where you go, everyone is taking pictures with their digital cameras. Part of the intrigue of digital photography is the instant feedback; after all, with a digital camera you can check and see if you need to re-take the photo. You might even feel a little creative and start changing some of your cameras setting to reflect your inner artist. That’s what makes digital camera so much fun; you can experiment and witness the results instantly.

Make sure and visit our site using the link at the bottom of the article. You'll be able to see photo examples!

Our digital camera LED Laser Etching Trick is super EASY to do and will create some truly creative photos. We’ve used it many times and each time people look at the photos with a bewildered look trying to figure out how the photo was created.

To the rational mind this type of photo tends to violate our sense of order. Cameras record objects, whether they are moving or stationary. Once we press the shutter our brains are fully prepared to see whatever we took the picture of, frozen in time. What our brains are NOT prepared for is to see a photo where the camera has frozen AND recorded the “track” of an object, which in this case is a simple LED light.

I have even had experienced digital camera owners look at an LED Laser Etching Trick and ask, “So you didn’t use video to do this?” When it comes to digital photos most people think in a linear manner and the LED Laser Etching Trick is cool because it forces our brains to think dimensionally.

If you try to explain the trick to someone without showing them an example they’ll act like they understand, but in reality, they really don’t. On the other hand, if you show someone an LED Laser Etching photo, they will be INSTANTLY intrigued, no matter what level of photographic experience they might have.

You see the fun part here is when you show someone an LED Laser Etching Trick you don’t need to say anything; the response is ALWAYS the same…

Wow, how cool!

And the next question is always…

How did you do that?

In fact I was at a party the other day and I pulled out my compact digital camera and then handed a small LED light to one of the guys and just said, would you help me with a trick? I gave him a cursory explanation and he was simply not impressed, period.

You see in his brain it was going to be a stupid photo of him standing there pointing the LED at the camera, big deal. That’s because his brain has been conditioned to the idea of how digital cameras work, no mystery here.

Until…

I showed him a photo that looked as though he had etched it in the air with a laser beam.

OK, so here’s a guy that initially was less than interested…

Now he’s running back and forth to the camera to see his latest laser etching creation.

This guy went nuts! Once he saw how cool it was he wanted to try all sorts of LED laser etching designs. Smiley faces, Christmas trees, the legendary Zorro “Z”, a crown, he went on and on. In the mean time more and more people were aware of what was going on and after a while literally EVERYONE wanted in on the fun.

Here’s the trick

I used a point-and-shoot digital camera and a cheap LED key ring light, or in other words, no fancy equipment.

My camera was set to “Fireworks” and since I didn’t have a tripod I winged it and just held the camera as steady as possible.

Note: For more consistent results it would be best to have secured my camera on a tripod.

Next, I went into a room that was fairly dark and handed the guy the LED light told him to point the LED at my camera and for a test just do a bunch of “squiggles” in the air. This was to give him an idea of how much time he had to “write in the air.” Since this was a basic point-and-shoot digital camera the only control I had was to set it on “fireworks.” No manual controls, nothing, just a plain old digital camera.

However, I knew with the “fireworks” setting the cameras lens would stay open longer than usual, long enough to record the LED light moving through the air. Now I know there are going to be people say that because it was hand held for so long the background AND the guy were going to be blurry.

Hey, all I was after was a neat looking creative photo; I really didn’t care if everything in the background was blurry.

I just wanted to record the motion of the LED light.

Then I held the camera up, told the guy to get ready, took a deep breath, pressed the shutter, and told the guy, GO.

Remember no flash, just nice and dark.

It took a couple of test shots for the guy to see just how much time he had to write. As I said though, once he saw the results he wanted to try all sorts of designs.

Ideas to try:

• Use two different colors of LED lights at the same time.
• Have 2 or 3 people with multiple lights at the same time.
• Use a larger standard LED flashlight.

In Summary

This technique is for standard point-and-shoot digital cameras with basic settings. If you own camera that has manual settings you can hold your shutter open for much longer periods of time for more creative flexibility.

Either way, auto or manual control this is just a fun trick and impresses absolutely everyone, give it a go!

http://www.digitalcamerau.com/2006/12/26/digital-camera-led-laser-etching-trick/

Etched Glass: Etching Beauty

Etched glass is a wonderful gift to give those that you love. The method of actually etching the glass can be done by you or by a professional. No matter who does it, by digging into the first layer of the glass, a shine and detail can be added to the glass, transforming it from a simple gift into something truly beautiful. But, why should you add etched glass to your list of things to purchase and give? There are actually several ways that this type of method can dress up your gifts and create a very unique and special look.

Etching can be done on many types of glass and other materials. For example, if you want to dress up the look of a mirror, you can etch the glass in a pattern. In a circle framed mirror, etch an intertwining vine long the edge of the frame, leaving the center completely open for viewing. It adds texture and depth to the look so that you get a more interesting piece to hand on your wall.

Etched glass can also be an ideal way to add element to your framed pictures. You can use etching to dedicate a picture or message. Or, you can use etching as a way to communicate with others the date and time of what happens in the photo. You can etch a poem onto the glass that is only visible if you really look for it. These things can help to transform an average piece of glass and an average frame into a meaningful, beautiful sentiment to the memory being depicted.

You can find professionals that sell ready made etched glass products. You can also find a number of different products on the market to purchase to help you to create your own etching. Whatever you do, find a way to create a beautiful image with the help of etching. You will adore all that it can provide to you.

For more observations about picture frames from Chad, click the link.