How to do Relief Printing with Solar Plates – ScreenPrinting Tutorial

Fun in the Sun: Greeting Cards with Solar Plates
by:  Curtis Taylor

This article will explain how to make fine art relief print cards using only the power of the sun. Unlike traditional printmaking methods that require dangerous chemicals or sharp tools and years of technical practice a solar plate uses the sun, some water, and a tooth brush to develop. This project will walk you through your first fine art creation with a solar plate avoiding years of art school not to mention the expense.

Solar plates are made with a special photopolymer that hardens when exposed to a UV light source. UV light sources can be purchased or made but I prefer to use a free source of UV light we call the sun. For our purposes solar plates are quite forgiving. You can work in normal indoor lighting conditions with incandescent or fluorescent light bulbs. There is no need for a darkroom. You just need to be careful to avoid direct sunlight until you are ready to expose your plate. Solar plates should be stored in a cool, dark and dry place until exposure. Solar plates are quite durable and will probably last a lifetime under normal hand burnishing.

Supplies:

  • Solar plate(s): At least one plate that is at least the size of your card. You can save money by purchasing larger plates and then cut them down to size yourself. Suppliers: Dick Blick Art Materials or Solarplate.com
  • Toothbrush
  • Washing tray: A flat cookie sheet larger than your solar plate with a sheet magnet taped or glued to the bottom
  • Relief print ink: water or oil based, any color. Suppliers: Dick Blick Art Materials, Speedball
  • Soft rubber roller. Suppliers: Dick Blick Art Materials, Speedball
  • Plate glass or Plexiglas (two pieces): larger than the solar plate
  • Hand clamps: these could be as small as paper binder clips for Plexiglas or construction grade for the heavier glass plates.
  • Barren: commercial or homemade I used a large wooden spoon as my barren. Suppliers: Dick Blick Art Materials, Speedball
  • Stationary: the size of your plate
  • Timer: any timer that can give you 30 second breakdowns
  • Cleaning supplies: based on the kind of ink you use
  • Utility knife: any kind will do but I prefer one with retractable blades
  • T-square straight edge: for guiding your utility knife
  • Source inspiration/material: your sketches or clippings you will use to create your image
  • Frosted Velum
  • No slip shelf matting: cut one just smaller than the glass plates and another one just smaller than the solar plate
  • Graph paper
  • Tracing paper
  • Rags: disposable

Before you get started with your solar plate you will need to determine what size greeting card you want to create. You can create a card any size you wish but keep in mind if you want to mail your cards you may want to keep it a standard size to avoid extra postage. I will be creating cards that will fit in the A4 (5 ½” x 4 3/8”) sized envelopes. This is a common card size and precut stationary is easy to find. However, the main reason I use that size (8 ½”x 11”) is because I can cut my solar plate into 4 equal parts that will fit nicely on a card without any wasted plate.

Designing Your Card:

1. Use your inspiration/source material to create your image. For this example I used an image I found on the internet and sized it for my needs then arranged it with text in a box the size of my solar plate. I prefer doing the designing on the computer because I can fine tune different aspects quite easily. Then I printed the image. If using a computer isn’t your thing you could use cutouts from magazines, your own card making materials or even free hand your image if you wish.

 

image 1

2. Trace your image. Trace the outlines and a few details just so you get the impression of your image. This is where you get to express your artistic vision and make the image yours. I traced my picture three times (see image 1) and added a curl before I was happy with my artistic interpretation of the cupcake.

image 2

3. Decide which parts you want to print (see image 2). Remember you are essentially making a photo negative. Everything you want to print you will leave UN-colored so the sun can harden that part of the plate. All the parts colored will remain un-exposed and will be washed away when you develop your plate.

image 3

4. It is time to trace the image one last time on a sturdy substrate (a base material that you will trace your image on). I used frosted velum because it is sturdier than tracing paper and the texture holds my opaque marker quite well. (see image 3) Trace the outlines of your finished image and then lightly mark (just in case you make a mistake) all the places that NEED to be colored in.

image 4

5. Use an opaque marker. The key term is “opaque” because if the sun can shine through, it will harden the plate. If your marker isn’t opaque your plate may look like this (see image 4) after developing. That plate will not work for this project but if yours does look like that don’t throw it away. We will use that plate in a future project. Use your opaque marker and color in the parts you labeled in Step 4. Hold your image up to the light. If you can see light shining through the marker or paint then you need to color your “blocked” parts more. I used an acrylic paint marker and put two layers on it before I felt it was opaque enough. If in doubt paint again, you won’t be sorry you did this. Let your image dry and be sure to tape or weight down the corners to prevent your paper from curling when it dries.

image 5
image 6

6. While your marker is drying, mark the backside of your plates so you can divide them into four equal parts with a utility knife. Using a T-square hold your plate firmly and use a utility knife to score on that line. (see image 5) After several cuts the utility knife will be guided by the groove it has made. Continue to use the T-square for safety while cutting through the back of the solar plate using medium pressure. You will need to repeat this movement until you eventually cut through the plate. Resist the urge to bend the plate at the score mark as it will only bend the plate at the points that are still connected or worse separate the photopolymer from the plate. Avoid metal snips as they tend to damage the edge of the photopolymer beyond use. Repeat the cutting directions on the two smaller pieces. (see image 6)

image 7
image 8

7. Take your dried image from Step 5 and place it face down on the polymer. (see image 7) Sandwich the solar plate and the image between the glass plates and clamp them so the image doesn’t shift on the plate (see image 8).

image 9

8. It’s time to expose your plate to the sun. This first exposure will be the hardest for you to gauge your exposure times and you may need to repeat this step again with a new solar plate if your first attempt doesn’t develop correctly. You can visit my website to see sample exposure times from South Dakota and southern California as well as some helpful exposure tips. I would suggest calibrating your exposure times at “high noon” whenever that may be in your part of the world. My shortest exposure time in Southern California was 2 ½ minutes in the direct sun at noon during the summer and 3 minutes in South Dakota under the same conditions. My notes tell me that I rarely did a 4 minute exposure and that was in South Dakota in the dead of winter and through a living room window. I would suggest starting at 3 minutes and if fine details get washed away during developing then add another 30 seconds. If the plate looks like the example in Step 5 then cut back 30 seconds. Place your solar plate sandwich in the sun and set an angle so it is directly facing the sun. (see image 9) Don’t worry about the occasional shadow or cloud.

image 10
image 11
image 12
image 13

9. Bring your exposed plate indoors. Remove it from the glass and your source image. If some of the marker or paint sticks to the solar plate don’t worry because that will wash off while you develop the image. Before you start look at the plate you should be able to see your image “burned” into your plate. (see image 10) Move to the sink and place it in the washing tray. Fill the tray with cool water to about half full. Use your toothbrush to lightly scrub the entire solar plate. (see image 11) While you are scrubbing the plate, you will start to notice some changes. The color of the plate will start to wash away from unexposed areas (see image 12) and you will start to feel different textures because the sun has hardened parts of the plate. This could take 10 minutes or longer but don’t stop until all the undeveloped film has been washed away. (see image 13) You can dump the water in the tray and refill if it becomes too hard to see your plate while you are scrubbing.

10. Check to make sure there is no film left behind especially in hard to reach places such as near any lettering or the edges of your plate. Softly scrub any trouble areas of the plate with your toothbrush while keeping it submerged in your washing tray.

11. Rinse your plate with slow running water and pat dry with a paper towel. Do not linger with the paper towel as the developed image will become sticky and your towel will likely stick to the photopolymer. Do not use cotton fiber towels. The fibers will stick the damp plate and will be difficult to remove.

12. Put your developed solar plate back into the direct sunlight and let it sit for at least 10 minutes. This will help dry the plate and it also hardens the plate so it is useful for printing. If it doesn’t harden completely then the plate will be weak and brittle. Extra sun at this point won’t damage your plate so don’t worry if you forget about the plate and it spends a couple hours in the sun.

image 14

13. Make a paper jig. This jig will help you line up your plate and paper properly and can be used over and over for cards that use the same sized plate. I use graph paper and draw arrows to the corners where I need to align my plate. I draw another set of arrows for paper alignment. Draw a quick image of your plate on a sticky note and arrange it on the jig so you will have a quick reference guide every time you bring an inked plat to your jig (see image 14) . If you get ink on your paper you may want to think about covering it with a piece of plastic so ink can be easily wiped off after every plate and avoid unwanted ink on your card. Avoid making notes on the jig where the stationary will come in direct contact with the jig because you may transfer some of the graphite or ink to your stationary after burnishing.

image 15

14. Arrange the no slip shelf matt under the glass. This will keep the glass from sliding when you are rolling ink on it. Squeeze a small amount (the size of a dime) of ink on the glass towards the top. This will give you room at the bottom to ink your plate. Start rolling through the ink making a square about the length and width of your roller. Continue rolling from top to bottom left to right then change hands and repeat. This will help to spread the ink evenly on the roller which will help achieve a uniform layer of ink on the solar plate. Continue to spread the ink in a wider area if the roller is making a spiked texture in the ink. The spikes mean there is too much ink on the roller and too much ink on your roller will make a mess on your plate. (see image 15)

image 16

15. Arrange the smaller no slip shelf matt under your solar plate, ideally on top of the same piece of glass as the ink to avoid messy cleanup of the counter. Roll the ink on your image. You will want to work in different directions to ensure an even layer ink is deposited on your image. Again work top to bottom a few times then re-ink your roller as you did in step 14 then roll the ink left to right a few times. Use a rag (I use cut up t-shirts) to remove any accidental inking that may have occurred. (see image 16)

image 17

16. Move the inked solar plate to your jig from step 13. Ideally the jig should be a sturdy level surface about waist high so you can use your weight to help burnish the image onto the paper. Align the inked plate with the markings on the jig and carefully align the stationary with the marks that are furthest away from the inked image. Keep medium pressure there so the paper does not slide and gently drop the paper onto the inked image plate. (see image 17)

17. Pick up the barren and start rubbing the paper directly over the image keeping pressure on the paper with the other hand so the paper doesn’t slip. Use as much pressure as you can and still be in complete control. Using a circular motion rub from top to bottom then start over at the top and rub left to right moving top to bottom in a circular motion to ensure you have pressed every part of the inked image.

image 18

18. Pull the stationary from the plate starting with the edge furthest from the image and gently peal it up and off the solar plate in a steady motion. (see image 18)

19. Let cards dry thoroughly.

20. Brighten up your cards with a little color.

Don’t lose your plate! We will use it again next time when we will explore different techniques for coloring your creations. I will be explaining how to add color to your prints using multiple plates and a few other traditional methods as well. Get ready to explore the possibilities with me.

Visit my website www.curtistaylor.biz for extra samples, templates and tips for using solar plates. If you have a question you can e-mail me at info@curtistaylor.biz.

 

Notes:

Calibrating exposure time: You can visit my website to see my exposure times from South Dakota and southern California and adjust your times accordingly. Keep track of your exposure times for future reference. I recorded my exposure times on an old calendar (the days of the week change but not the dates) to keep as a quick reference guide for exposure times.  I kept notes such as time of day, exposure length and the weather conditions for each plate in this calendar.  From this first plate you can make educated guesses on exposure times thereafter because we know the sun is most powerful around noon and during the summer.  Keep notes from each plate and after two seasons, say summer and fall, you will be able to accurately gauge exposure times for the rest of the winter and the coming spring. I would suggest starting calibrating your exposure times at “high noon” whenever that may be in your part of the world.

My shortest exposure time in Southern California was 2 ½ minutes and that was in the direct sun at noon during the summer and 3 minutes in South Dakota under the same conditions. My notes tell me that I rarely did a 4 minute exposure and that was in South Dakota in the dead of winter and through a living room window.  I would suggest that you start at 3 minutes. If fine details get washed away during developing then add another 30 seconds.  If the plate just won’t wash clean during developing then subtract 30 seconds from your exposure time. Once you have calibrated your exposure time you start exposing your solar plate in the morning or afternoon add thirty to sixty seconds to your exposure time depending on the position of the sun.  Don’t worry about the occasional shadow or cloud.

Water based or oil based inks?  Water based inks are easy to cleanup many times requiring only a water rinse and less toxic.  However water based inks can smear or bleed into other water based coloring techniques such as markers or watercolor paints even if the ink is dry. Oil based inks are nearly permanent on paper or cloth and won’t run or bleed if colored over with water based markers or watercolor paints.  However oil based inks are harder to clean up but can be done with little cleaning chemicals.

This first exposure time will be the hardest for you to gauge your exposure times and you may need to repeat this step another time if your plate doesn’t develop correctly.

TIP: When you are designing your card keep in mind that you will want to leave a small margin around the outside edges of your image so it won’t get printed over the fold line if your plate or paper slides while printing.

TIP: Make sure the photopolymer side of the plate is resting on paper so you don’t accidentally scratch your plate.  Also, avoid touching the photopolymer as much as you can before developing and make sure your surface is completely dry.  One drop of water will start developing the plate and it won’t expose properly.

Tip: Look at the image and note areas that didn’t print correctly.  Does it need more ink or more pressure? Look at the solar plate to see if there is extra ink in the trouble areas.  If there is extra ink then you need more pressure in that spot.  If there isn’t extra ink on the image then you didn’t apply an even coat of ink. Blotchy ink marks mean you used too much ink.

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