Monday 18 November 2013

OUGD504- Content

-Block printing

INTRO
Block printing is one of the oldest types of printing. Block printing can be done with many materials such as metal, plastic, rubber and even potato but this example will focus on using wood. An image is carved into the wood leaving raised areas which are then inked up with a roller. The inked surface is then transferred to the material you want to print onto by applying pressure. The sunken areas are left un-inked which reveals the colour of the paper. Block printing is typically done by hand, this produces a bold print, with the ink leaving a slight raised texture to the paper.

Tools
-Cutting Tools
-Bench Hook
-Roller
-Palette Knife
-Spoon

Materials 
-Oil based ink 
-Wood
-Material you want to print onto

Preparing your artwork

The first step is to sketch your design on to the wood. This will form the template for your printing block. For more complicated designs, you can trace an image using tracing paper, place the drawing face side down and rub the back to transfer the image to the wood.  If you are going to use text you will need to reverse it to allow it to print the right way round. A good tip is too fill in the areas with a marker you want to carve, this will help to visualise the print.

Preparing The Wood Block

The wood is ready to be carved. Use the bench hook to hold the wood and carve out the parts you do not want to be printed. Always remember to cut away from yourself when carving to avoid an accident. Once you have finished carving, make sure any excess chippings are removed so they don't affect the print.

Printing

To prepare the ink, use a palette knife to spread the ink onto a glass surface in a straight line. With a roller, dip it in the ink and roll out an even layer until the ink has a tacky quality to it. Once the roller is evenly coated, carefully roll it onto the wood block. Do it once in each direction to make sure the raised areas of your design are evenly covered.

The quickest method of printing is to press the block onto paper by hand, making sure you apply an even amount of pressure. 

Another way is by spoon. Put the wood block ink side up on a flat surface and lay the paper over the top. Rub the back of the sheet with the spoon evenly to transfer the image onto the paper. This method requires some patience but can produce a really nice finish.Once you have finished, carefully peel back the paper and leave to dry.



-Lino-cut

INTRO
Lino-cut is a similar process to block printing. It works the same way by carving an image into the lino, leaving raised areas to be inked up with a roller. The inked surface is then transferred to the material you want to print onto by applying pressure. The sunken areas are left un-inked which reveals the colour of the paper. Lino-cut is an effective but simple process that produces subtle variations making each print unique. 

Tools
-Cutting Tools
-Bench Hook
-Roller
-Palette Knife
-Spoon
-Press

Materials 
-Oil based ink
-Lino
-Material you want to print onto

Preparing your artwork

To prepare your artwork you can simply draw directly onto the lino. If you want to use a design you have created on a computer you will need to print the image with a laser printer.This is called the toner method. Remember to reverse your image on the computer for it to print the right way round when printing.

Preparing The Lino

To transfer the image onto the the lino, place the laser printed design facedown. You will need to wet the back of the paper with Bestine solvent or acetone. Rub the paper lightly to transfer the image then gently peel it off the lino.

Your lino is ready to be carved. Use the bench hook to hold the lino and carve out the parts you do not want to be printed. Here you can experiment with various cutting tools to make some interesting marks and try out different cutting depths for thicker lines. Always remember to cut away from yourself when carving. Once you have finished carving make sure any excess lino is removed.

Printing

Before you can start printing you will need to set up a registration page to allow you to place the lino and your paper in the correct place every time. To do this, on a piece of newsprint, you will need to outline the size of the paper you will be printing onto. Place the lino in the centre and mark the outline.

To prepare the ink, use a palette knife to spread the ink onto a glass surface in a straight line. With a roller, dip it in the ink and roll out an even layer. Once the roller is evenly coated, roll it onto the Lino. Make sure the raised areas of your design are evenly covered.

Depending on what facilities are available to you, there are two methods you can use. The first is by hand. Place the paper you are wanting to print onto on top of the inked up lino, make sure it lines up with registration marks. Use a spoon and rub the back of the sheet to transfer the image onto the paper.

The second method is printing with a Columbian Press. Place the registration page with the inked up lino on top of the press board, make sure the lino is lined up with the registration mark. Place the paper on top with a sheet of newsprint on top of that and cover with the press blanket. This will help to apply the pressure evenly when being pressed. You will need to lower the cover and turn the handle. This will position the bed under the platen. Pull the lever towards yourself to press the image, then release. Use the handle again to release the bed, remove the newsprint and carefully lift of the paper. The ink will take some time to dry so place it somewhere practical.  



-Emboss/Deboss

INTRO
Embossing is a process that presses an image into a material to create a raised area above the material. Debossing works in the opposite way, the area around the image is pressed down to leave an indent. To emboss/deboss an image, a plate is pressed against a material under high pressure to leave an imprint. The final result ends in the structure of the paper being altered for a delicate finish that can add a professional quality to your work. 

Tools
-Palm sander 
-U.V. exposer unit
-palette knife 
-Press

Materials 
-Copper plate 
-Wood plate
-Acetate
-Photo-polymer
-Magic tape 
-Oil based ink
-Material you want to print onto

Preparing your artwork

To prepare your artwork you will need to print your image onto clear acetate with black ink. You can print the image with an inkjet printer, laser printer or photocopier. Depending on how you print, will affect the amount of time you will need to expose the image. If you are using a wooden plate, which is explained in the 'preparing the plate' section, you will need to create you artwork in illustrator. Make sure you turn your design into vectors (lines), this is so the laser knows where you want it to cut. Remember to reverse the design so it will print the right way round.

Preparing the plate

There are two types of plates that can be used to emboss/deboss. To create a plate to emboss, it is more affective to use a wooden plate. To create a wooden plate the quickest method is to use a laser cutter to cut out the areas you want to be raised for the paper to be pressed into. Remember to reverse your image for it to print the right way round.

To create a plate to deboss, you will need to prepare a copper plate which is a little more detailed. This technique is called photo etching. To remove any scratches from the copper you will need to sand the plate with a palm sander. Sand the plate in a circular motion until any scratches are removed. Once you are happy, you will need to wash the plate with a sponge and liquid degreaser to remove any finger marks. This will stop any air bubbles once the film is applied. Make sure you rinse the plate thoroughly and blot dry with some newsprint.

The plate is now ready to be laminated. Cut the light sensitive photo-polymer so its slightly bigger than the plate. Place the plate onto the rolling press board and peel off the inner layer of the photo-polymer and carefully place it over the plate. Make sure you don't touch the plate with your fingers. Place the acetate with your image on over the top of the photo-polymer, remembering to reverse the image and roll it through the press slowly. Once it has gone through the press, spin the plate 90 degrees and roll it back through the press. Trim the excess photo-polymer so its flush to the plate and secure the acetate over the top with magic tape. The magic tape will let the light through when exposing.

You are now ready to expose the plate. Place it face down onto the U.V exposer unit. Depending on how you printed your image you will need to expose it for different times. The times are measured in light units.

Ink jet acetate 3 L.U.
Laser printer acetate 8 L.U.
Photocopier acetate 8 L.U.

Next you will need to mix some sodium carbonate into a tray of water. Remove the plate from the exposer unit and peel off the top layer of the photo-polymer. Place the plate into the water and gently sponge the plate every 30 seconds for two and a half minuets. Remove the plate from the water and blot dry with newsprint. Once the plate is dry, place it back into the exposer unit face down and further expose for 60-80 light units to re-harden the remaining photo-polymer. All you need to do now, is tape up the back of the plate to protect it from the acid. Place the plate in the ferric acid tank and leave for around 7 hours. To etch the plate evenly make sure you rotate the plate halfway through. 

Printing

Before you can start printing you will need to set up a registration page to allow you to place the plate and your paper in the correct place every time. To do this, on a piece of newsprint, you will need to outline the size of the paper you will be printing onto. Place the plate where you want it to be pressed and mark the outline.

There are different techniques of embossing however this example will focus on two types. The first is blind embossing. This method does not use any ink. Place the registration page onto a board and align the plate with the marked outline. Align a sheet of paper over the top and cover with a stack of tissue paper, this helps to apply pressure evenly across the sheet. Its best to use the hydraulic nipping press for embossing because it allows you to apply a lot of pressure. Slide the board into the side of the press and tighten the screw on the side. Pump the handle towards yourself until it becomes tight, press the black button on the side and continue pumping the handle until it becomes difficult. Loosen the screw on the side to release the pressure and remove the board. Take off the tissue paper and carefully peel back the sheet and place some where to dry.


To second method uses ink. The ink preparation is the same as block printing and lino-cut. Use a palette knife to spread the ink onto a glass surface in a straight line. With a roller, dip it in the ink and roll out an even layer. Once the roller is evenly coated, roll it onto the plate. For the printing, simply repeat the same process as above. 




-Letterpress

INTRO
Letterpress was the first commercial printing process. It uses individual, moveable lead blocks of type that are arranged and secured into a frame. The raised areas of type on the lead blocks are inked up with a roller and pressed onto the paper. Letterpress produces a high quality handmade finish with a focus on craftsmanship. As all the type is set by hand, the process can take sometime so keep this in mind.

Tools
-Lead type blocks
-Spacers/Leading
-Composing stick
-Chase
-Furniture
-Coin
-Allen key
-Press

Materials 
-Oil based ink
-Material you want to print onto

Preparing your artwork

With letterpress the preparation is done by hand when preparing the type. However, to make life easier for yourself it can be a good idea to draw out your design to help you understand how to arrange the type and to make sure you have no spelling errors. To make life even easier, once you have your final deign, reverse the image on a computer and print it off so you can refer to it when setting up the type.

Preparing the type

You have to set the type by hand so you will need to select the individual letters you want to print. Place the letter blocks in the composing stick, if you are printing a sentence for example, you will need to place spacers between the words, think of this as pressing the space bar on a computer. If you have more than one line of text, you will need to place leading beneath each line. Remember to the arrange the letters upside down, from right to left and in reverse so it will print the right way round. Now your sentences are ready to be transferred to the chase. Place some leading at the top and bottom of the type and carefully lift it out of the composing stick and place into the centre of the chase. Fill the space around the type with pieces of furniture. You will need to arrange the furniture to allow space for coins. The coins are needed to hold all the pieces together. When you have arranged all the pieces you will need to tighten the coins with an allen key. The chase is now ready to be secured to the press bed.


Printing

There are different types of presses that can be used for printing but this example will focus on the flatbed cylinder press. Before you can start to print you will need to ink up the rollers on the press. To do this you need to spread the ink along the top roller. Turn on the press and the rollers will start spinning, spreading the ink evenly across all rollers. Turn the handle to rotate the barrel forward, this will ink up the type.You should do this a few times to make sure all the letters are evenly covered.

Next you need to secure the paper you are printing onto. There will be a foot pedal that needs pressing down to open the barrel clamps. Keep the pedal held down and align the paper underneath. When you release the pedal the clamps will snap shut, holding the paper in place. You are now ready to print. Turn the handle to rotate the barrel, this will roll the paper over the type, transferring the ink onto the paper. Roll the barrel back to the starting position and released the paper with the foot pedal. Place the paper somewhere safe to dry.
 

-Screen printing

INTRO
Screen printing is the equivalent of using a stencil. A wooden or aluminium frame is covered with a delicate, fine nylon mesh that the ink is squeezed through. The stencil can be made by placing paper under the screen, by digital or hand drawn imagery that is exposed onto the screen with light sensitive emulsion. For each colour in the image, a separate screen and stencil is required. Screen printing is good for printing onto a variety of materials and allows you to create multiple prints for cheap.

Tools
-Screen
-Squeegee
-trough 
-palette knife
-U.V. exposer unit 

Materials 
-Acrylic Ink
-Binder
-Emulsion
-Brown tape
-Material you want to print onto

Preparing your artwork

Before you can start the screen printing process you must prepare your artwork. Most artwork is created in Illustrator. If your artwork has more than one colour it will need to be separated into layers. The colour layers need to be printed on separate pages but both printed with black ink to create the positive images.  Black ink is used to prevent light seeping through when you come to expose the image.

Preparing the Screen

Before you can prepare the stencil, you must make sure the screen has no ink, grease or old emulsion on it. If it does, apply stencil remover to the screen with a sponge  and wash off with the pressure washer to remove some of the tougher stains; this is also known as degreasing. Place the screen in a warm room to dry. The screen must be completely dry before the emulsion is applied.

Once the screen is dry you can apply the light sensitive emulsion. To apply the emulsion, fill the trough about half way. Place the trough with the emulsion in at the bottom of the screen at an angle and pull the troth up in a smooth motion whilst keeping contact with the screen until you reach the top. Its best to apply a thin layer of emulsion to the screen to allow the image to expose properly. Once the emulsion has been applied, place the screen in a dark area and allow to dry. Make sure you clean the trough afterwards.

When the emulsion is dry, you are now ready to expose your image in the UV exposure unit. Place the positive image face up on the glass bed and align the screen, emulsion side down on top of the image. Close the lid and switch on the vacuum pump. This stops light escaping from behind the positive areas of the image.Expose the image for 170 L.U. 

The emulsion becomes hardened when the UV light comes into contact. The dark areas of the image don't allow the light to harden the emulsion.Rinse of the screen gently with water to remove the soft emulsion, the hardened emulsion remains to form the stencil. once the screen is clear, place it in a warm room and allow the screen to dry.

Printing

To prepare the screen you need to tape the inside edges with brown tape to protect the screen. The screen is now ready to be clamped onto the screen bed. Before you start printing you will need to secure a clear, hinged sheet of paper with registration marks on to allow you to print the artwork in the correct place. Once you have done this turn on the screen bed vacuum.

To prepare the ink you need to mix 1/3 acrylic paint with 2/3 binder. Mix the ink and binder together and spread the ink evenly in a line at the top of the screen with a palette knife. Place the squeegee behind the ink at a 45% angle and apply pressure, pull the ink across the image. Lift the screen up slightly, this will turn off the vacuum. Push the ink back to the top of the image ready for the next print. Lift the screen fully and position the paper you are printing onto under the registration marks, masking tape one corner of the paper to mark the positioning for future prints. Remove the clear sheet of paper and lower the screen. You can now repeat the process to produce multiple prints. Keep in mind the ink will dry out after while.

If you have any left over ink once you have finished printing, scrape it up with a palette knife and put it in a sealed container to use next time. Remove the screen from the bed and scrub the screen with stencil remover with a sponge, use the pressure washer to make sure you remove any remaining ink and emulsion. Once the screen is clean, place it back in a warm room to dry, ready for the time you want to print.




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