THERMOGRAPHY UPDATE: THERMOGRAPHY OFFERS EXPANDED OPTIONS FOR PRINTERS WITH IMPROVED LASER-SAFE TECHNOLOGY

By John McTigue

The professional look and feel of thermography, also known as raised printing, makes it a leading choice for business cards, letterhead and invitations. As laser printers and high-speed copiers became the norm in businesses throughout the last two decades, thermographers faced a unique challenge - how to prevent the raised images and lettering that make thermography so desirable from melting during use on this equipment.

The thermoplastic quality of traditional thermography powder allows it to re-melt at high temperatures. This was causing the raised lettering to smudge when sent through high-speed copiers or laser printers. The reason is that normal thermography powder is what is called thermoplastic - meaning it can be melted over and over again with enough heat. So what happens in the laser printer is the fuser roller used is hot enough so that when it comes in contact with the thermographed image, it will remelt, smear or flatten the raise.

The manufacturers of thermographic powder faced this challenge head on by creating both a new powder and a new processing system. These two elements allow for completely laser-safe results.

How It Works

Thermographic printing is a multi-stage process. First, a printed paper drops off the printing press onto a conveyor. The conveyor moves the sticky ink underneath the thermography powder which is shaken on top of the entire sheet. The powder attaches to the wet ink. The extra powder is then vacuumed up and stored for re-use. Next, the coated sheet passes through an oven with temperatures ranging from 900 to 1300 degrees Fahrenheit. In order to obtain the best thermographic printing results, off-set equipment is recommended, although the process can be completed by using letterpress equipment as well.

There are currently two methods for ensuring laser-safe results in thermography. The first method combines a specially formulated powder with an ultraviolet light used to harden or cure the raised stationery so it won't re-melt. This can take place on an in-line machine or the conveyor of the thermography machine combined with a retrofit unit. This is the most productive and cost-effective procedure and produces a smoother finish on fine lines of type, almost resembling genuine copper plate engraving.

The second method, called the thermographic curing system, utilizes the same special powder but requires an increased curing time. In this process, the conveyor belt is slowed down by 40 percent so the paper has extra time in the heat tunnel to cure. The finish is also rough.

Follow the Rules

For best results with laser-safe thermography, review the following checklist:

Do not put more than 20-25 sheets at a time in the laser printer or copy machine.

Heavy solids or large bold type is not recommended, as the finish gets rough and may crack on large areas. A new and improved power is now being developed which will overcome this.

Determine your customer's needs. The process is not designed for a mass mailing, but instead for specialized printing needs. The raised print on envelopes makes the envelopes thicker, consequently impeding the feeding process.

The ideal use of thermography is standard stationery without large solids, providing your customers with the professional look and feel of raised printing.

So, how can laser safe thermography help your bottom line? Thermographers across the country are reporting major increases in laser safe business including stationery, envelopes and letterhead. WPT Board member John McTigue, President of Business Card Express in Marlton, N.J., reported a 42 percent increase in laser safe letterhead business in the past three years and Duane Harrison, WPT Board member, and President, Utley Brothers, Inc., Troy, MI reported a 46 percent increase. Both thermographers report that their customers switched to flat printing for a short time while these laser safe methods were being perfected. Now, their customers are returning for that professional raised image look of thermography.

John McTigue, president of Business Card Express in Marlton, N.J. is a board member of the Worldwide Printing Thermographers Association (WPT), headquartered in Washington, D.C. WPT's mission is to promote and advance the art of thermography as well as the use and application of the thermographic process.