| Audio-Visual Communication Handbook |
|Basic production Techniques|
Pictures cut from magazines or other sources, maps and charts printed on paper, and photographs are likely to get damaged when handled frequently. To make pictures and charts last longer, they can be mounted on cloth, cardboard or heavy paper. Pictures can also be protected by covering with glass or clear plastic and binding with cloth or paper tape.
In addition to providing protection, mounting makes pictures or small objects more attractive and easier to use. The method of mounting will be determined in part by the intended use. Is it to be held up in front of a small group? Is it to be handled extensively? Will its use be temporary or relatively permanent? These questions need to be answered before deciding the type of mounting to be used. If planning to mount many illustrations in a picture tile so they will last longer and can be handled without damage, try to standardize the size of the mount. This will make storage easier.
No matter what process is used to mount pictures, take the time and care necessary to make the mount neat and clean. The extra work is well worth the effort in its effect on an audience..
Paste or Gum Mounting
Paste or gum mounting is satisfactory for mounting magazine illustrations or photographs onto heavy paper or cardboard. Commercial white paste or gum arabic can be purchased in almost any book or stationery store. In the few cases where such adhesives are not readily available, a flour and water paste, of either commercial wheat or cassava flour, can be mixed for an equally good adhesive. When mixing paste, first, be sure all lumps are smoothed out. Second, since flour is a favorite food for insects, add a small quantity of insecticide to the paste an important precaution in areas where insects are prevalent. A safe insecticide powder works fine, but don't use a liquid insecticide because the petroleum base is likely to damage the picture. Exercise care when using and storing paste that has been treated with insecticide, particularly around children. They sometimes eat paste.
The steps for mounting with paste or gum are relatively easy.
1 With a pencil, mark the cardboard or paper lightly where the picture is to be located. As a general rule, side margins should be of equal width, and the bottom margin should be slightly wider than the top.
2. Apply adhesive to the back of the picture with a wide brush or a piece of stiff cardboard. Use only enough to cover the back of the picture adequately.
3. Carefully place the picture on the mount. Cover it with a clean piece of paper and rub down carefully.
4. Remove any excess adhesive, allow it to dry, and erase any pencil lines that show.
Although using a paste or gum adhesive is a reasonably satisfactory method for mounting pictures, these adhesives may dry out in time which may cause the picture to come off the mount. Also, they change color with age, the result being some discoloration of the picture.
Rubber Cement Mounting
Rubber cement is one good adhesive for mounting pictures. Tire patching cement and shoe repair cement can also be used, and are available in most countries. These adhesives are relatively permanent and easy to use. If rubber cement cannot be purchased, it can be easily made in areas where raw rubber is available. The formula is given in Appendix 4.
For a temporary mount, the steps in rubber cement mounting are similar to those for paste mounting, but the procedure for a permanent mount is a bit different. For the latter, the adhesive must be applied to both the picture and the mount. The steps are:
1. On the cardboard or backing paper on which the picture is to be mounted, make light pencil marks to indicate where the picture is to be located on the mount.
2. Coat the back of the picture and the front of the mount with a thin layer of cement. Use a brush or piece of card. Be sure to cover both areas completely. Try to avoid excess amounts of cement beyond the picture area.
3. Allow the rubber cement to dry completely.
4. Before letting the picture touch the mount, be sure it is positioned accurately since the two rubber cemented surfaces will stick tight on contact. This step can be facilitated by using two pieces of waxed paper such as a waxed bread wrapper. Cover the cemented surface of the mount with the pieces of waxed paper and move the picture until it is in exactly the proper position on the mount. Then carefully slide out the waxed paper. Finally, cover the picture with a sheet of clean paper and rub down carefully, working from the center to the edges of the picture.
5. Remove any excess cement by rubbing the cement into a ball with a finger. Be certain fingers are clean to avoid smearing.
Dry Mounting is a simple, fast procedure for mounting pictures or photographs in countries where dry mounting tissue can be obtained.
In the dry mounting process, a sandwich is made of the picture, tissue, and mounting paper or cardboard. Then pressure and heat are applied. A regular household electric iron or an iron heated on a stove or with charcoal can supply the heat. The steps are:
1. With the tip of an iron, tack a sheet of mounting tissue to the back side of the picture. Tack in the center. Special tacking irons are sold for this purpose, but a household iron works equally well.
2. Trim picture with attached tissue to the desired size with a razor blade and ruler or straight-edge.
3. Position the pictures and tissue carefully on the mount. Lift tower left hand and upper right hand corners of the picture and tack the tissue at these points.
4. Cover the picture with a clean sheet of paper and rub it with the household iron. When an electric iron is used, set the temperature of the iron to rayon heat. Covering prevents direct contact of the iron and picture, which can cause the ink with which the picture was printed to melt and smear. The heat adheres the picture, tissue, and mount.
Heat can also be applied with a dry mounting press which is taster and more convenient, particularly when much dry mounting work is to be done.
The wet mounting process is useful for mounting paper maps, charts or other pictorial material onto cloth. The process is called wet mounting because a water-base paste is used as an adhesive. Materials that have been mounted on cloth can be handled repeatedly and rolled or folded for storage with little chance of damage. To wet mount, the following materials are needed:
1. Wheat, rice or cassava flour (or a similar substitute) to make a paste. Put the flour in a jar with holes punched in the lid. Crushed moth balls can be added to keep insects from eating the paste.
2. A wide paint brush for mixing and applying paste, and a shallow pan for mixing.
3. Unbleached muslin, baft or old flour sacks, for the cloth backing.
4. Thumb tacks or drawing pins for attaching the cloth to the mounting board.
5. A wooden rolling pin or a smooth bottle to roll the mount smooth.
6. A bowl or similar container for soaking the backing cloth.
A flat surface on which to do the mounting is needed. A table is ideal, but remember that paste and pins will damage the surface. A piece of thick plywood makes a good working surface. Two coats of waterproof varnish or shellac will prevent the cloth from sticking to the board. The following steps outline the wet mounting process:
1. Pour about one-halt cup of water into the mixing container. Sift in the flour, stirring it with the brush. Mix it carefully to prevent lumps from forming. Add flour until the paste is thick enough to spread easily.
2. Wet the cloth thoroughly. New cloth will resist water, so be sure it is completely wet. Wring out to remove excess water.
3. Lay the cloth on the working surface and smooth out the wrinkles. Fasten one corner with several thumb tacks or drawing pins. Stretch the cloth keeping the threads straight, and fasten two adjacent corners. Fasten the cloth at the middle of each side keeping it stretched tightly. Complete pinning of each side by working from the center to each corner. Space the pins about six inches apart.
4. Place the material to be mounted on the smoothly stretched cloth and mark the corners with pencil.
5. Next, place the material to be mounted face down on a smooth surface and moisten the back with water by using a sponge or piece of cloth. The material should be completely saturated so that it lies flat.
6. Apply paste with a wide brush to the surface of the stretched cloth, extending beyond the pencil marks. Be sure the paste is spread evenly and there are no lumps. Work rapidly so that neither paste nor material can dry out.
7. Carefully lift the material and place it in position on the cloth. It the material is large and difficult to handle, told it loosely, paste-covered sides out, before lifting it to the paste-covered cloth. Working from the center toward the edges, smooth carefully. Take care to avoid tearing the soft paper or getting paste on its surface.
8. Use a rolling pin or round bottle as a roller to smooth out excess paste and to make a permanent mount. A set pattern of rolling will reduce wrinkles and air bubbles. Roll from the center to one end of the mount. Then roll from the center to the opposite end and follow by rolling from the center to the top and from the center to the bottom.
9. Lift the corners to relieve tension built up during rolling.
10. Roll from the center to each corner. The rolling pattern should form an X. Roll carefully from the center toward the edges. As you roll the edges, avoid getting paste on the roller. Clean paper strips placed over the edges of the map or chart will prevent paste from getting on the roller. When the rolling is completed, remove the paper strips and wipe off any excess paste with a damp cloth.
11. Allow to dry completely before removing it from the working surface.
The edges of the cloth mount can be finished in several ways to make a neat edging. If cloth-backed charts are to be used outdoors, the edges can be strengthened by folding the edge over a piece of heavy string and sewing it in place.
Flat pictures or small objects that need protection can be framed with glass or clear plastic and tape. Carefully done, this is an attractive way of displaying magazine pictures, photographs' or various kinds of certificates. Framing protects as well as improves the appearance of visuals. Materials needed are a piece of glass or plastic; a piece of cardboard slightly larger than the material to be framed; and paper or cloth tape at least a half-inch wide. The process of mounting a picture is as follows:
1. Mount the picture on the cardboard with paste or rubber cement.
2. Mark the glass with a crayon about a half-inch from each of the four edges.
3. Place the glass with the marked edges down. Apply face to each side, using the crayon marks as guides. A small, wet rag or sponge is good for moistening gummed paper tape.
4. Turn the glass over, trim the edges of the tape, and cut the corners as shown in the diagram. Then, wipe off the crayon marks.
5. Again turn the glass over, place the mounted picture face down on the glass, and carefully fold the tape around the edges of the glass onto the cardboard.
Colored tape can be used or paper tape can be painted with water colors. The finished mount can be displayed on an easel or, before framing, a string can be attached to the cardboard backing so the picture can be hung on the wall. To attach a string to the cardboard backing, follow this procedure:
1. With an awl or some other sharp tool, make two holes through the cardboard backing about two inches apart and a third of the way down from the top of the mount.
2. Thread string or cord through the holes and tie with a square knot on the back side of the backing. Make the loop short enough so it does not show above the backing. Cut off the excess cord and pull the knot tightly against one of the holes.
3. On the inside of the mount, flatten the cord with a coin or some other smooth. hard object.
4 Cover with tape to prevent the cord from slipping
A picture can be mounted on a separate piece of heavy paper or thin card. Since paper can be obtained in many colors, this permits a wider choice of backgrounds.
A frame that is open at one end can be made which makes it possible to remove and replace a picture. The procedure for making an open-ended mount is similar to that previously described. In addition to the glass cardboard backing, and tape, several strips of cardboard about 1/4" wide are needed:
1. Cover one end of the backing and one end of the glass with tape.
2. Glue strips of cardboard to the remaining three sides of the backing. These strips will act as spacers to separate the backing from the glass. Then, tape the glass and cardboard together on these three sides.
The finished frame can be displayed on an easel. Fasten a small piece of tape to the pictures to make them easier to remove from the frame through its open end.
Mounting three-dimensional objects such as seeds, butterflies, cloth or mineral samples is similar to mounting a flat picture. Wood or cardboard spacers must be placed between the glass and cardboard to make room for the objects or specimens being framed and to prevent cracking the glass. The cardboard spacers can be made by gluing or cementing several cardboard strips together. The thickness of the spacers will vary according to what is being framed. Cement the wood or cardboard spacers to the backing.
Absorbent cotton can be used under the objects or specimens to hold them in place. If specimens such as butterflies, moths, etc. are being framed, add a few moth crystals to prevent their being eaten by live insects. A cardboard mask can be used to frame the objects. Place the objects in position, cover with glass, and tape the mount by using the same procedure for framing flat pictures.
Many kinds of objects can be taped-framed. Use ingenuity to discover new materials to mount or new ways to make the mounts more attractive.