Introduction: Thermochromic Ice Cream Print

About: Specializing in sewing, soldering, and snacking.

Create your own temperature reactive (thermochromic) print that animates when you are playing out in the hot summer sun. This summertime print is a delicious looking ice cream cone that gets a bite taken out of it when it reaches a certain temperature. It's sure to remind everyone around you that ice cream is what is needed in the sweltering heat. The print is made by screen printing onto fabric. The designs are then cut out, becoming iron-on patches for easy placement on whatever your heart desires. My heart desired a nice thin and cozy white tee.

This 'ible provides the designs for the cone and uses a super quick and dirty way of screen printing. If you have a good setup, or have your own screen printing method, go with that. This shows how to set up a very simple, table-top screen station, how to cut and attach the designs to a t-shirt. Let's get started!

Step 1: Gather Materials

Fabric Paints

- Thermal Dust, Rubine Red 86ºF

- Liquitex Fabric Medium, 4 oz.

- Light brown fabric paint, 2 oz.

- Cream fabric paint, 2 oz.

Listed below are the paints I had around the studio, I needed to mix 3 together to get a color close enough to what I needed. Martha Stewart's craft paint can be used on fabric, as well as other mediums. It's best to find a color that matches without mixing. Choose a color of any brand of fabric paint that is closest to the Rubine Red with mixed with the fabric medium. The best way to know if its a match is to dab the same amount on white fabric and drying it. When paint dries it will become darker.

- Martha Stewart Satin Craft Paint, Raspberry Ice, 2 oz.

- Red fabric paint, 1 oz

- Blue fabric paint, 1 oz

- 1/2 yard of white light - medium weight cotton

Other Materials

- White t-shirt or another item to iron on final designs. It can be anything, just make sure to match the fabric the designs are screened on with the item that they are ironing on to.

- Roll of 1"-1.5" wide masking tape

- 5 mixing cups (4 for colors, one for water)

- Mixing Spoons

- 10" x 14" printing screen

a larger one can be used, this can be useful to print more designs at once

- Screen printing squeegee, small

- 1/3 to 1/2 yard of acrylic craft felt, or large scraps of felt or other smooth, lofty material

- Hair dryer

- Scissors or rotary cutter

- Metal ruler

- Access to a slop sink to rinse screen in

Step 2: Mix and Distribute Paint

Make a cup of each:

1) Cream (cone)

2) Light brown (texture and cone outline)

3) Thermal dust + fabric medium (top of scoop)

Put the dust in the cup first, add the medium a little at a time until it's a good consistency and mix until it is smooth in appearance.

4) Thermal dust matching pink

The ratio came to about 2:1 pink to red with a tiny dash of blue. It's easiest if you find a paint that matches without mixing. If mixing, pour in the pink and gradually add the red. Dabbing it on white fabric with the thermal dust mixture, drying it and comparing.

5) Water

To rinse any spoons or brushes used for mixing or touch ups.

Step 3: Cut Stencil

The best way to cut a stencil is to do it out of sticky vinyl. Cutting from anything else may not last for many pulls and unreliably produce crisp lines. To print a vinyl stencil for screen printing, a vinyl cutter is used. These can be found at some printer services and maker spaces.

The designs were created in Illustrator. They are attached for download and to use with whichever printer and bundled software available to you. If you like, make register marks to line up each layer, this will save you vinyl in the long run and possibly some headache. This particular design is small and simple enough that I chose to eyeball each layer while printing. Attached is an illustrator file of each layer, and one that has each color layer as an illustrator layer, where everything is lined up. I use a Roland VersaCamm. Prep the image for the printer, making sure to leave a 2" - 3" margin around the design so paint doesn't seep through. Send it to the print and the blade will follow the created cut lines.

Print an extra stencil for testing and doubles if you want to print more than 6 cone designs. I wanted to print 9, so I cut 2 of each layer.

Step 4: Prep and Attach Stencil

The print layers go in this order, first to last:

- cone

- scoop

- scoop top 86ºF heat reactive paint

- cone texture

- cone outline

The first stencil to screen is the cone design. After each layer is printed, the screen gets washed and the stencil removed.

Take all the negative spaces out from the cut design using something sharp, like a large hand needle or awl. Cut the stencils down to 10" x 14" (screen size). Gently peel off the backing, taking care to not tear the vinyl where there is detail in the design. Stick it on the side of the screen that will touch your fabric, smoothing it out making sure there are no wrinkles.

Tape the stencil around the edges of the, filling covering any remaining gap between the screen frame and the stencil.

Step 5: Prep Print Area

The work surface to print on just needs to be super smooth. If printing on thin materials, such as the white cotton, it helps to have a small cushion to press into. This is what the felt is good for, it's also good for any paint that seeps through very thin material. That shouldn't happen with the fabric for the this project.

Cut some felt that is the screen dimension +5"- 6" in width and length. Tape down one layer to a work table around the edges, pulling the felt taut lengthwise and widthwise, making it nice and smooth.

Next, cut the fabric being printed on and tape it to the felt, pulling it taut as well.

Step 6: Test Print

Check the screen to make sure it's clean of any debris that could spoil the fabric.

Position the screen on the fabric, checking placement by looking the through the screen to see where the designs lay.

Scoop some paint onto the screen along one side of the design. I screened side to side, it may be more comfortable to screen from top to bottom, whatever feels right. Spread the paint with the spoon so it extends past the full length of the design.

Clamp or hold down firmly, you don't want the screen to slip as the paint is applied.

Hold the squeegee at a 45º - 60º angle, or drawing a line from your nose to the top of the squeegee. Place it directly above the paint, with even pressure, slide it across the design. Press down firmly, not too firm that would cause the squeegee blade to bend. The paint needs to be pushed down through the cutouts, but not sideways between the screen and fabric, which will result in blotchy designs.

I did two pulls, one each way, on all designs except the cone texture/outline, that got one. Ideally it would take one pull, but it may take more.

Be careful not to pull too fast across the design.

Do some test prints to get a feel for pressure, pull number and speed. Once comfortable, it's time to move on to the final prints!

Step 7: Lay Down First Color

Position the cone design, thinking where room needs to be left for repeat prints. A 10" x 14" screen holds 6 designs. I screen printed 3 at a time in 3 rows. So, when positioning each row, I made sure there was enough room for other two.

Once you have screened over a design, it's difficult to place because of the opaqueness of the paint. This makes each design good for one screen print. Once you have screened a design or row of designs, scoop up extra paint off the screen and put it back in the cup. Turn the screen over and tape over the screen design. Overlap the tape 1" past the design's outline so paint doesn't seep past the edges. Work quickly if using super opaque paint, if this paint is left on the screen for too long, it will clog the mesh and be difficult to get out. Adding fabric medium will help thin the paint and prevent clogs. If you create register marks for lining up each layer, then you won't have to worry about this.

After the first layer is down, you are ready to clean the screen and squeegee. Remove the stencil and wash the screen thoroughly using water. For stubborn paint, use a brush with mild soap.

Use a hair dryer to speed up drying between layers.

Step 8: Print the Rest

Attach the next stencil in the same way as before. Print the rest of the layers, lining them up with the previous designs and drying in between each one. The remaining layers are:

- scoop (pink)

- scoop top (pink 86ºF heat reactive paint )

- cone texture (light brown)

- cone outline (light brown)

Step 9: Make Fabric Iron-on

Remove the fabric from the printing surface and all tape around edges.

Flip the fabric over so the back side is facing up. Cut pieces of Heat n Bond large enough to cover the designs. Place the Heat n Bond, shiny side down and iron down on a med-high temp setting.

Wait until the Heat n Bond cools down completely. Flip over and cut out each ice cream cone design. The paper backing can be removed before or after the cuts. Keep the paper on if they are to be used later.

Step 10: Iron on Designs

Grab a t-shirt, bag or what ever you like to apply the designs to, as long as it's the same color as the fabric you screen printed on.

Play with placement of the design, putting some tape on the back helps keep them on without pinning while trying things on to test placement.

Pin down the designs when the placement is decided. Take over to the ironing board and set the iron to med - high temperature. Iron down each design from the front to make sure the designs stay in place. I tacked attached the cones, applying most of the heat there, rather than over the thermochromic paint. Turn the fabric over and iron from the backside to ensure that the adhesive melts.

The design changes at 86ºF, even if it's not that hot outside, direct sun will make it nice and toasty in no time. It will also change from body heat, so do not iron the designs to a form fitted garment or something that will be in contact with the skin constantly.

You are done! Now get out in the sun and eat some ice cream!

Step 11: Get Out in the Sun!

The design changes at 86ºF, even if it's not that hot outside, direct sun will make it nice and toasty in no time. It will also change from body heat, so

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