For my friend's birthday I wanted to create something a little more special by using led lights to make a light up card. I have used Chibitronics led lights that are made for paper craft projects but I wanted to try led lights I bought from Amazon since they are much cheaper.
First, I chose a few cupcakes from the Baker's Dozen stamp set by Papertrey Ink and stamped it onto watercolor paper in a loose pattern. The paper is cut in the usual A2 card size. I used Versafine Smokey Gray ink as it is water resistant. Taping down the sides of my watercolor card, I used my Gansai Tambi Pearl Colors watercolor set to add different colors to each of the cupcakes. The tape should prevent the card from warping too much as you watercolor. There's no need to be super exact for this type of watercoloring.
I have a spray bottle to spritz water onto the card first, then swished each color over the cupcakes with a watercolor brush, letting the colors run naturally. You can go back and add more color if you feel like it needs more emphasis. Let your card dry, or use a heat gun. I got some heavy books to squish my card flat while I worked on the led light circuit.
To determine the location where the led light should be placed, I made a small hole in the star of the middle cupcake. Placing it over my folding card base, I used a pencil to go through the hole to mark a spot onto the base card. I decided I would place my battery on the bottom right side of the card, then drew lines where the copper tape should lay. Then I laid the copper tape following the lines, flattening each stripe with a bone folder. Once I figured out which side was the positive and negative on my led light, I used Ranger Multi Medium Matte glue on the back of the led light to glue it down to by card. I had to really get the led pressed down onto the copper tape so I left a few heavy books on top and let it set.
Once that's set, I used three layers of double sided foam tape to line the sides of the card. You will need to create a box around the battery with the foam tape so it won't slide around inside the card. It also needs to be high enough above the battery so that the watercolor card will not be pressing on top of the battery constantly. Place the watercolor card on top of your card base and press firmly. Now when the bottom of the card is pressed down, the light should shine right where the star is.