With all the great new digital printing technology being offered to the sign industry today, some might think that the old methods of screen printing signs and decals would be seriously outdated and perhaps dead or at least dying. Though some things that once were screen printed can now be produced faster and with less setup costs with today’s miracle printers, still there are many sign-oriented products that are far better screen printed. For this varied group of sign products, the production speed, low cost and high outdoor durability of screen printing makes this medium the most practical and most profitable way to go even in this high-tech era.

Back in the 70’s, I posed for this photo with a squeegee I had made from tire rubber. Screen printing sign orders in quantity was the only way to go then. But, even with new digital printing technology available today, for some types of sign production, screen printing is just as viable today and far from dead.

A short list of these screen printed products include corrugated plastic yard signs, political signs, high volume decals, banners, flags, metal warning and safety signs, real estate signs, and so forth. When the quantities are more than a dozen or two, and the requirement is for outdoor durability, screen printing is likely to be the very best choice. Some of these items could be printed using today’s digital printers, using sublimation, and so forth, but the cost per square foot to print them could never compete with screen printing when any kind of volume is involved.

Signs like these, needed in multiples and necessarily outdoor durable, are still best done by screen printing. Low cost of production and good weather resistance are typical of screen printed signage.

Of course, this doesn’t mean all sign businesses must also be screen printers. Subcontracting the larger volume orders out to a reliable wholesale screen printer is a logical solution for many commercial sign shops. For example, if a mostly vinyl shop gets an order for 75 single-sided 3x6 banners from a local boat manufacturer, it would be foolish to do them all in vinyl graphics. The profit margin and the quality of the product offered to one’s customer would likely be higher by merely subbing out the job to a screen printer.

ARTWORK & SETUP
Most wholesale printers will work from digital files or camera ready art, but the sign shop manager can lower the art or setup charges by producing film positives themselves and sending them on to the screen printer. Film positives for spot colors with no close registration are as easy to produce as applying graphics plotted in black ip or hp vinyls onto a clear polyester sheet. Polyester sheet (Mylar) can be bought in 2-mil thickness on a roll, much similar to acetate, at very low cost and black vinyl is in every sign shop in the country.

Smaller screen printing film positives (up to a legal size piece of paper) can be made on a laser printer printing on translucent media. Our Samsung ML-1740 printer costs less than $200 and does a great job of making small film positives in just a few seconds. The special sheets of translucent paper or plastic film are available from any screen print supply house.

For those who may not know it, the reason film positives are usually one of the first steps in screen printing setup is that the main stencil types used by screen printers are made from photo sensitive products which are put into a screen and then exposed to bright light through a film positive. The image on the film positive blocks the light from hardening the stencil material under the image, so when the screen is rinsed out with water only the image area dissolves and opens up for printing.

TAKING THE PLUNGE
Virtually all sign companies can produce designs for screen printing with their sign software, and can likely produce their own film positives as well, making dealing with wholesale screen printers fairly easy. But, what would motivate a sign shop owner/manager to take the plunge and go into in-house screen printing? What factors should be weighed in making such a strategic decision?

For a low initial investment in supplies, tools and materials, a sign maker can set up to do manual screen printing and still tackle those jobs requiring dozens or even hundreds of prints.

First of all, having a good demand for items that are best done by screen printing is likely to be the most motivating factor. For instance, if a particular market is demanding a local source for larger orders of corrugated plastic signs (for contractors, politicians, realtors, etc.), then there could be good profits to be made in being able to complete such orders in-house. Also, steady demands for metal safety signs, warning signs, no this-and-that signs (for industry, agriculture, pipelines, security companies, etc.), can signal a significant opportunity for producing work that’s best done by screening.

Printing with a modern “clam-shell” press is fast and easy, but requires a considerably larger investment.

Some of the things that would be required to venture into sign shop screen printing would include enough work and storage space for a screen printing area and places to put screens, inks, drying racks, tools and so forth. Also, the fire code applying to a specific building or zoning area, plus the ability to provide excellent ventilation must be considered since most all screen inks, reducers, cleaners, etc. are solvent based.

If the sign company’s facility would lend itself to having a screen printing area, and the market and potential profits are there, then what would it take to actually get started? What would it cost? How difficult will the learning curve be?

An entire book could be written to answer these questions, but relying on personal experience, I will try to offer at least some of the answers to questions like this and suggest some practical ways to get started without breaking the bank, and with the least amount of stress.

Though it would be nice to have a $25,000 budget to work with in setting up a screen printing department within a commercial sign shop, and even $2,500 would work well, one could actually (and in fact I have already) get started in profitable screen printing on a budget of well less than a thousand dollars. This is partly due to the fact that most sign shops have a lot of the essential equipment and capabilities in place already.

To keep down our ink inventory, we have found that we can print on nearly all substrates with only two kinds of ink. A good enamel ink (NazDar 5900) bonds to painted metal sign blanks, glass and acrylic plastics and any substrate oil-based paints would stick to. A good multi-purpose ink (NazDar 9700) bonds to vinyls, most plastics, and corrugated plastic sign blanks if a 5% amount of catalyst is added.

A small array of screens and squeegees could be purchased for $400 or so, and the inks and at least one type of stencil system could be added for the same amount or less, and using the software, plotters and so forth in the shop already, one could be off to the races. This assumes, of course, that someone actually knows a bit about sign shop screen printing...

THE MOST ESSENTIAL ELEMENT
Yes, here’s the most essential element to get started without undue stress and a proliferations of mistakes: a skilled person on hand to advise and direct the movement into sign shop screen printing.

Do you need someone to come into your shop for three or four evenings, and do hands-on demonstrations of screen printing setup and basic printing techniques? And, walk your personnel through the first couple of jobs to get everyone up to speed and teach them how to do the work correctly and trouble-shoot their mistakes? Yes, this is ideally what a beginner should experience, but I’m afraid I don’t know anyone who has a career as a traveling instructor, and I don’t yet have the time to do it...I wish I did. But when I retire, that would be a fun job, alright!

But back to reality, though you could read, and ask questions, buy videos perhaps, and jump in willing to learn by one’s own mistakes (and that’s how we did it), the best strategy would be to find someone who could coach you through the beginning steps and the first big learning curve. If not, the strategy we took may have to do, but it will be more interesting (read: frustrating) that way. It still can be done.

ABSOLUTE ESSENTIALS
What equipment is absolutely essential? A $12,000 pneumatic clamshell printer would be nice, but manual printing can get a whole lot of work done at very low cost. Direct-applied stencil film, water-based and knife-cut on a plotter will work quite well (UlanoCut Amba is a good one), and you already have the plotter. Even photo sensitive stencils, film or emulsion can be used and exposed to sunlight with excellent results, requiring only a scoop coater, and dark room for drying, and a shaded wash out tank of some type. (Our excellent washout tank was a brand new fiberglass shower unit that a fork lift driver poked a hole in, which we repaired with a .040 alum patch, a few rivets and some silicone. The plumbing supply house gave it to us just to haul it off.)

Some hardware and tools would be required. A few squeegees in lengths a couple of inches longer than the substrate sizes to be printed would be needed. We use 70 durometer (hardness) squeegees for flat stock we print, and softer 60 durometer squeegees for printing on corrugated plastic sheets.

A pair or two of screen hinges, which are actually screen-clamping hinges, would be nice, though I have used regular hardware store hinges many times, especially on jobs that I want to leave set up on a scrap of plywood ready to print again at a minute’s notice.

Drying racks will be needed, but they can be very simple. Many of our jobs are dried in racks, which are merely sign stakes for fluted plastic signs laid over wooden strips. These are stacked up to 30 high, and later break down and go in boxes. Pieces of 2x4 lumber grooved with shallow cuts spaced about 1'' apart, cut with a radial saw, make excellent drying racks for small metal and rigid plastic signs.

Screens, the inside dimensions of which are about 8'' to 10'' wider and at least 12'' longer than the image being printed are of course essential. They can be wooded framed screens, but may best be made by professionals so that the screen tension is very tight and uniform. (A good screen manufacturer happens to be local to our area, Sunbelt Mfg. in Longview, Texas 1-800-333-8412.) The standard mesh for sign printing is around 155 threads per inch, and white fabric should do fine.

And,
Inks! Inks! Inks! One could stock a warehouse full of inks for different substrates. There are inks for fluted plastic, inks for poster stock, and inks for metals. There are inks for acrylics, polystyrene, vinyl decals, and a special ink for each of 50 kinds of plastics. Fortunately, most sign shop printing can be done with two types of inks, if you know how to use them. We stock a good enamel ink (NazDar 59000 series) for printing on all painted substrates including metals, wood, and even glass and acrylic plastics. For many plastics, vinyls and fluted plastic we use a multi-purpose ink (NazDar 9700). This ink is easy to print with and bonds to many synthetic substrates, even corrugated plastic if a 5 percent amount of catalyst is added (NB-70).

Narrowing down the ink inventory is essential for cost, storage and even fire code concerns. We stock all the main colors in just two ink types, plus the reducers for each. Retarding reducers (slow drying thinners) are best for most work, especially for beginners, since the ink will not dry so fast in screens while printing.

CLEAN AIR AND CLEAN-UP
As mentioned, very good ventilation (to the outside of the building) is needed. Again, we found a great but inexpensive way to move the air away from our printer and outside at our shop. Cutting a couple of holes in a metal building wall is easy enough, and the power ventilators that anyone can buy at a home improvement store only cost about $50 each, and move a good volume of air. We installed two of them over holes in an outside wall and had them wired with on/off switches into a 120-volt circuit at the shop. They were positioned to draw air away from the operator of our semi-automatic printer and through the drying racks holding freshly printed signs.

For cleanup of enamel printed screens, simple mineral spirits and then dishwashing soap and water work fine. For enviro-friendly cleanup of screen jobs printed with 9700 multi-purpose ink we use a soy bean based solvent called Inkee-Doo (from FranMar, 800-538-5069). And yes, we wear latex gloves when cleaning ink from screens with any solvent or thinner.

As I mentioned when talking about ventilation, we own and use a semi-automatic press (M&R Saturn) though we did manual screen printing only for years. We also have a shop built mechanical press that we use for some jobs as well. Except for the M&R Press and an inexpensive fluorescent/vacuum exposure unit, most of our screen printing equipment has been accumulated over the years, borrowed from other purposes, devised from our own ideas, and scrounged. But we have long had the ability to do a lot of screen printing, in-house, for many kinds of work that routinely come through the shop.

For us, having the capability of doing our volume jobs in outdoor durable screen printing has always been a great asset. For many types of work, it is by far the most practical and profitable of any available method, even today when there are numerous and newer methods of printing available.

No, sign shop screen printing isn’t dead, or even on its way out. Through subcontracting, it is an available and profitable avenue for any sign company. But for those who have the space, the tools, and make the effort to learn the techniques involved, screen printing is still an ultimately viable, practical and profitable way to pursue success in the sign business.