Screen Printing Real-Estate Signs

Today, signpainting and screen printing are considered two different crafts, but this was not always the case. Signpainters in New York and Chicago developed the technology that became what we now know as screen printing. I ran a screen printing business for many years and I screen printed numerous signs for my own customers and for local signpainters.

Screen printing may seem daunting at first, especially in the middle of the first-printing run, when the inexperienced screen printer drops the squeegee, splashes ink on several completed signs and pokes a hole in the screen just as the phone rings. However, screen printing is really a fairly simple process that can produce an attractive, profitable product with a modest investment of time and money. If you can cook, you can screen print.

Like cooking, your screen printing will improve with practice, but your first experiments are likely to be embarrassing if you don’t follow instructions carefully. Screen printing vocabulary Before I get started, I want to explain some screen printing vocabulary. The process we’re going to use is called screen printing, not silk screening or silk screen printing. Using the word "silk" in this context immediately identifies you as a complete novice or someone whose training and experience are 30 years out of date.

The mixture of pigments, binders, viscosity modifiers, solvents and other chemicals that we will use to decorate the sign blank is called "ink" – not "paint" – even when we run out on Saturday morning and buy an emergency gallon at the local Sherwin-Williams store. The screen consists of a frame of wood or metal, stretched with mesh made of polyester fibers (this is what happens to bad leisure suits when they die).

The mesh count is simply the number of threads per linear inch that are woven into the mesh. In addition to the ink and screen, the one other indispensable tool of the modern, high-tech screen printer is the squeegee. (Don’t blame me, I didn’t name it.) Squeegees are available with wood or metal handles. Save money by buying wood. The squeegee blade is a thick, rubbery piece of plastic; do not economize on the blade. Get the best the supplier has to offer; generally, a proprietary variation of polyurethane.

Good squeegee blades print better and last longer. Squeegee blades come in various hardnesses. Ask for a medium hardness. (By the way, the longer the squeegee, the more difficult it is to print with, so it’s a good idea to always print with the squeegee running parallel to the shortest dimension of the sign. However, the squeegee should be at least 2 in. longer than the widest design you plan to print.) The real-estate signs we’re going to print are 18 x 24 in.

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We’ll print with the squeegee running parallel to the 18-in. dimension, so we’ll need a squeegee 20 in. long. The tools of the trade In addition to screens, inks and squeegees, you will need the following tools and supplies: A screen printing "jig" consisting of a printing surface (a smooth table top or sheet of plywood will do) with hinge clamps attached (see photo 1) A box full of shop rags to clean up the mess afterwards Practice blanks (Sheets of paper or cardboard that you can practice printing on before you start printing on your expensive sign blanks) Ink stirrers Clean ink-mixing cans Plastic gloves A plastic or heavy cloth apron A kick leg – a wood slat that attaches to the frame of the screen to hold it off the surface of the printing jig when you’re between prints (see photo 8).

Lots of old newspapers

Several pieces of 5 x 8-in. cardboard In addition to the ink, you should order one quart each of two ink modifiers: reducer – to adjust the viscosity of the ink; and retarder – to slow the drying of the ink in case this happens in the screen. Also purchase a gallon of screen wash to clean the screens and squeegees after printing. Various types of ink require different reducers, retarders and screen washes.

The supplier who sells you the ink will also sell you the appropriate products in these categories. You will need a drying rack – a wooden jig or fixture to place the freshly printed signs on while they dry. (Laying freshly printed signs out on the lawn behind the shop invariable results in grasshoppers stuck in the wet ink and sudden, unpredicted rain squalls.) You can make a simple, cheap drying rack by cutting a series of saw kerfs slightly wider than the thickness of the sign blanks, about 1 in. apart and 3/4 in. deep across the (nominal) 4-in. dimension of a 2 x 4-in. board.

Lay this board on the floor with the saw kerfs up, where it will be out of traffic and away from dust, and you can slide the edges of the printed signs into the saw kerfs to hold so they can dry. You will also need a helper. Although an experienced screen printer can easily print an order of real-estate signs alone, this does not apply to your situation. Until you gain screen-printing experience, two hands and two feet just aren’t enough.

Your helper should hand you the unprinted blanks, take away and rack the printed signs, answer the phone and be prepared to wipe ink off the squeegee handle, your hands and the toilet seat. The sign blank Your first decision involves the substrate you’ll use. Whichever type you select, I strongly suggest that you purchase blanks that are cut to size and pre-coated.

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You may be strongly tempted to save money by buying large sheets and cutting and priming them yourself. Don’t do it. This is more work than it’s worth. Real-estate sign blanks must be rugged, cheap, durable and very printable. Although real-estate signs are occasionally printed on heavy, weatherproof poster board, the more commonly used materials include: corrugated plastic, which is good for 1-3 years of continuous exterior exposure; hardboard; expanded-sheet PVC; and coated sheetmetal.

All of these materials should be good for at least three years of continuous exterior exposure anywhere in North America. The determining factor will be which material your customers prefer, and how much they are willing to pay. Ink Selection Once you determine your sign-blank material, you can – with some advice from your screen printing supplier – select an ink.

Although special inks are formulated for each of the blank materials previously mentioned, in most cases, a good-quality, high-gloss, exterior-grade enamel will work well. This type of ink is relatively inexpensive, widely available, weather- and fade-resistant, adheres well to most surfaces, looks good and is very easy to print with and clean up.

The two materials that are exceptions are expanded PVC and corrugated plastic. Enamel will work on the PVC, but vinyl lacquers are better. If you intend to print on corrugated plastic, ask your screen printing supplier to recommend an ink specifically designed for that product. Avoid Day-Glo or fluorescent colors. Under the best circumstances, these colors will show significant fading in 60-90 days. Use them only if the customer insists, and warn the customers about the fading.

Designing the sign

Usually, real-estate agencies will bring an old sign in for you to copy, but if you’re starting with blank paper, here are some guidelines for designing real-estate signs. Real-estate signs are printed on both sides in one or two colors, rarely more. Make the design bold and easy to read from a passing car.

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The primary copy should be the name of the agency. The secondary copy should be the agency’s phone number. The easiest designs to print have white backgrounds, a good margin between the printing and the edge of the sign blank and don’t require tight registration between the colors. You can draw the sign full size in black and white (one drawing for each color), cut the design from red masking film, or create it on a computer and print the design out on a laser printer.

Buying the screen

At this stage in your screen printing education, I suggest that you don’t make your own screens. Most screen-printing suppliers offer finished screens with the design already imaged on the mesh, ready to print. When you order the screen, specify the inside dimensions of the frame, the mesh type and mesh count, and explain how you will provide the design to be printed to the screen maker.

Novice screen printers often make big mistakes by ordering their screens too small. Smaller screens are less expensive, but they are devilishly hard to use. Here’s a rule of thumb for screen size: The margin between each side of the design and the inside of the frame should be at least 1/3 of the image size.

Therefore, because we will print 18 x 24-in. signs, the inside dimension of the screen should be 30 x 40-in. I reasoned: 1/3 of 18 = 6, so the top and bottom margins must be 6 in. each; 1/3 of 24 = 8, so the left and right margins must be 8 in. each; 18 + 6 + 6 = 30; and 24 + 8 + 8 = 40. This is the minimum size. The mesh type should be monofilament polyester, and the mesh count is determined by the type of ink you will be printing.

After selecting the sign blanks, ask your screen printing supplier to suggest a type of ink. Then ask for recommendations as to proper mesh count. If the supplier recommends a range of mesh counts, select one at the lower end. Lower mesh counts are stronger and easier to print with.

If all else fails, request a screen with a mesh count ranging from 150-195. These mesh counts will work with almost any ink for printing real-estate signs. Setting up the printing jig After you’ve assembled all the supplies, sign blanks, ink and screens, you’re ready to set up a printing jig and practice. Bolt the hinge clamps to a large table top or piece of plywood, clamp the screen in preparation for the color that prints first in the hinge clamps, and then slide one of the sign blanks under the screen.

Be sure to position the sign blank so that, when the screen comes down, the image area is correctly positioned over the blank. Swing the screen up, then carefully mark the location of the bottom and one edge of the positioned sign blank. Tape or staple three registration stops (small rectangles of poster board or plastic about 1 x 2 in. [see photos 5, 6 and 7]) to the surface of the printing jig so that one of the stops is at each end of the bottom of the sign, and one stop touches the side (about an inch from the bottom).

The registration stops will ensure that you place every sign blank on the printing jig in the exact same position relative to the image on the screen. Next, you must adjust the off-contact distance (see photos 9 and 10). This is the distance between the bottom of the screen and the top of the sign blank when both are positioned for printing. Place a sign blank on the registration stops and lower the screen all the way down.

You must have a distance of 1/8-1/4 in. between the screen mesh and the top of the sign blank. You can adjust the screen up by taping spacers (washers or small thin scraps of wood) on the surface of the printing jig where they will hold up the corners of the screen that aren’t clamped into the hinge clamps.

The printing surface should be flat, and the off-contact distance even, across the entire surface of the sign blank. You may have to place shims between the bottom of the frame and the bottom jaws of the hinge clamps (see photo 11). If this adjustment is necessary, be careful not to move the screen out of register. You can also use short, round-headed wood screws in the corners of the frame to adjust the off contact.

Attaching a kick leg

The last step in setting up the printing jig is the attachment of the kick leg. Cut a light wood slat 2-3 ft. long (see photo 8). Drill a small hole through the slat about 3 in. from the end. Drill another hole about 1 in. into the edge of the bottom of the frame (about 1 ft. from the end of the frame away from the hinge clamps). Carefully drive a small screw through the wood slat and into the frame. (This is no place to get careless. You don’t want to damage the frame or tear the mesh at this point.)

The wood slat should pivot on the screw. This slat is the kick leg. When it’s turned with the long end down, it will hold the frame off the surface of the printing jig so that you can place and remove sign blanks. When it’s pivoted so that it is parallel to and flat against the edge of the frame, it allows you to lower the screen into the printing position. You can purchase ready-made metal kick legs with springs, that will lift the screen semi-automatically, and clamps, that will attach them to any screen from your screen printing supplier.

Once the screen, registration stops and kick leg are in place, you are ready for the ink. Open the can and stir the ink. Most screen printing inks are ready for use right from the can. The ink should have a viscosity somewhere between honey and heavy cream. It definitely should not be watery. If the ink seems too thick, pour the amount needed to print the job into a clean can and add a small amount of reducer.

Your screen printing supplier will provide you with data sheets for all the ink and ink modifiers they sell you if you ask, and these documents will have specific instructions. Do you have all the supplies and equipment on hand that you will need to complete the job? Screen printing is like ski jumping. Once you start, there’s no convenient stopping place until the end.

If this is your first time, you might want to unplug your phone, or at least turn on your answering machine. Place a practice blank in the registration stops, lower the screen and then pour about a cup of ink onto the screen between the image area and the side of the frame held in the hinge clamps.

Spread the ink a little toward the top and bottom of the frame and then make one print stroke across the image area of the screen. Do this by holding the squeegee in both hands, placing it in the ink pool, tip the squeegee handle about 15 degrees out of vertical in the direction of the print stroke, push the squeegee firmly down and pull the squeegee toward you. Here are some tips. You don’t have to move all the ink with every print stroke. Only pull enough ink to print the full image.

You don’t need to cover the entire surface of the screen with ink. In fact, a neat professional screen printer will only place ink on the screen where it is needed for printing. Try to avoid getting ink on the frame and the squeegee handle, at all costs. You should push down on the squeegee just firmly enough to bend the blade, but only slightly.

After the print stroke, you must make a "flood" stroke. Lift the screen a couple of inches and make a stroke in the direction opposite the print stroke with the squeegee blade held just a fraction of an inch above the screen. The purpose of the flood stroke is to cover the image area of the screen with a thin layer of ink without pushing the ink through the mesh.

Don’t worry, the ink won’t drip through the screen on its own, or if it does, you thinned it down too much. The layer of ink flooded over the image area of the screen by the flood stroke prevents ink from drying in the image areas of the screen and blocking the print. Practice printing and flooding until you are confident you can print a sign blank quickly and easily and obtain a sharp, even print.

You’re now ready to start printing the signs. Your sign blanks should be wiped free of dust and stacked where they are near the printing jig, but not in the way or where likely to splash on them. You should have 3-5 extra blanks on hand over to allow for misprints. Check your hands for ink smudges. You don’t want to leave your thumbprints all over the nicely printed signs.

Print the first color on one side of each of the blanks and stack each one neatly in the drying rack. If you have any smears, smudged prints or misprints, you can clean up the print, or remove the entire print with screen wash. Lay the misprinted blank on a clean table with several layers of old newspapers underneath.

Then, working quickly and making as little mess as possible, wipe clean the blank and then wipe it as dry as possible. Set the cleaned blank aside and print it last. After all the sign blanks have one color printed on the first side, you must clean the screen. Don’t remove the screen from the printing jig. Place several layers of old newspapers under the screen.

Put on plastic gloves and scrape as much of the ink out of the screen with the pieces of cardboard. Put the excess ink back into the mixing can. Next, dampen a rag with screen wash and wipe as much ink as you can off the screen. Keep wiping the screen on both sides with fresh rags until you have removed as much of the ink as possible. When you’ve done this, take a break. You deserve it.

Before you start the next printing cycle, you must let the ink you just printed dry thoroughly. I used to print real-estate signs at the end of the day, timing my work so that I finished cleaning the screen at quitting time. This gave the printed blanks the entire night to dry.

Once the print is thoroughly dry on the first side, print the same design on the second side. Then change screens, repeat the set-up procedure and print the second color on both sides just as you did the first. Here are some general tips if you’re new to screen printing. Screen-printing is a messy process.

Make an extra effort to keep you, your tools and your shop clean. If you don’t, you’ll find the ink in numerous unlikely and unwanted places. The screen printing process will seem awkward at first. Overcome it by practice printing before you start putting ink on your good sign blanks. Learn to be patient and work at a steady pace: not too fast and not too slow. You won’t gain anything by hurrying. Adjust your work schedule so that you can print each stage of the job without distractions or interruptions. Good luck.