On a camping trip with our new Cub Scout troop and their families, one of the projects that was done while we were there was to meet Elective 12a, making solar prints as part of the Nature Crafts Elective that we were trying to fulfill while on this camping trip.

The Cub Scouts all picked out their respective leaves, placed them on the black construction paper provided and placed one or two rocks on the leaf, before leaving it in a sunny spot to make the print.

My son's leaf solar print did not show up, (as shown in the last photo) and this was not acceptable to me - the crazy-Engineering-craft-loving mom who likes to see things through and to see them work.

We were given additional sheets of black construction paper to perform the experiment/craft at home, and one weekend of sunlight, we did just that.

I titled this Instructable "DIY Construction Paper Solar Prints" because I looked for online tutorials about performing solar prints, only to be disappointed in finding people purchased a special kind of solar paper to do their prints. Although those prints come out really cool with the color changing paper, we used the materials we had on hand (hence the less expensive route) and I was happy that all three of my children (ages 3, 4 and 8) were interested in the project and were able to do it.

Step 1: The (basic) Science Behind Solar Prints

As stated in the intro, my children and I did this project to meet a Cub Scout Requirement, specifically, Bear Elective 12, Nature Crafts. As part of that requirement, the Cub Scout is to make solar prints of three kinds of leaves (part a.) The Cub Scouts in the Bear Group are usually eight to nine (8 - 9) years old.

Depending on your use of this project, you could include a small discussion of what ultraviolet (UV) radiation is to enlighten the children. This is not a requirement for meeting the Elective, but it's good to get in a teachable moment with my 8-year old where I can.

For the purposes of this experiment/craft, what is occurring is that the UV rays of the sunlight are discoloring the black construction paper by a chemical reaction.

The black dye in the construction paper is breaking down in the sunlight, due to the ultraviolet radiation. The portion of the construction paper that is covered by the leaf (or leaves) is blocking the sun from breaking down the color in the construction paper.

While talking about it with my children, I compared this to getting a suntan. I described how the color on the paper was changing just like skin changes when you've been in the sun for a while. The skin under clothes doesn't normally get changed and stays the same color, just like the color of the paper under the leaf. Of course with the skin, it turns darker (or red) whereas the paper got lighter under the sun, but it still changed.

My 8-year old had his mind blown when he heard that the sun is 93 million miles away from earth, but compared to the other stars in the sky, it's only eight (8) light minutes away.

I found articles and great photos by NASA on various websites that can be used to talk about the sun and the effects of UV rays. The discussion could be done in greater detail depending on the age of the children and what the purpose is for.

Resources

Notes about the sun in general: Solar and Heliospheric Observatory site

An excellent description of the parts of the sun: How the Sun Works by How Stuff Works

A description of the different type of UV rays: Ultraviolet Radiation by Health Physics Society

A description of what type of UV rays are harmful to our skin: Stay Safe in the Summer Sun by the FDA*

*Note: There is a 2-minute video on this site that describes how the UV rays affect your skin and what sunscreen does for it.

Step 2: Materials

Construction Paper Solar Prints can be performed by using a variety of different things to hold down the leaf onto the construction paper. I used three different types of systems to make the print, and all of them worked well.

You will need:

black (or dark colored) construction paper, sized larger than your chosen leaf (ours were 9x12 inches in size)
leaves of different sizes and shapes (Gathered in Step 3)

You can use what you have from the three (3) different systems shown in this Instructable to hold down the leaf:

glass - such as a piece from the inside of at least an 8x10 (inches) picture frame
an 8x10 frame and a clear sheet protector
rocks of various sizes, for leaves that are large and don't have smaller leaves making it up

Optional, additional craft:

crayons and white sheets of paper for crayon leaf prints (shown in Step 4)

Step 3: Gather Your Leaves

My children and I walked to our neighborhood park and looked at all the different trees and types of leaves available to us.

Most of the leaves we ended up getting were from right in front of our own home, as I try to teach my children about property and how leaves are a part of a living plant. We did pick some of the leaves but they were all from plants right in front of our home.

The maple leaves were beginning to fall so those were easier to gather and they are big. Some of the other leaves we gathered were smaller, and my oldest chose a tiny leaf he found on a plant in front of our house.

Even I have to admit I didn't know there were so many choices for leaves right outside my door! What a great learning experience in itself.

Note that the NEXT STEP is OPTIONAL. Go onto Step 5 if you want to move straight to performing the solar prints.

Step 4: Optional: Leaf Prints With Crayons

My oldest son thought of doing this first before leaving the leaves out to dry in the sun.

It was a proud mommy moment and I went along with it.

Covering the leaf with a white sheet of paper, my children took a peeled crayon and rubbed the side of it over the leaf to make a print. All three participated, and we looked at the veins of the different leaves as well as how the edges compared to each other.

Step 5: Set Up Prints in the Sun

Select an area to place your solar print system where there is going to be at least four, preferably six hours of sunlight on them. In our case, I placed the papers directly on the concrete driveway in front of our home.

For each system, you will place the leaf or leaves on the piece of paper prior to placing anything over it.

To get the solar prints, place one of the following systems on top of the leaves and paper:

System 1 - Place the glass from an 8x10 photo frame over the leaves and paper. This should be heavy enough to leave in place for the day.

System 2 - Place a sheet protector over the leaves. Place the empty 8x10 photo frame over the sheet protector to hold the system in place.

System 3 - With larger leaves, rocks can be used to hold the leaves down to create the solar print. Place the rocks so that it covers only the leaf. This way the rock itself doesn't become part of the print (unless that's something you are trying to do!)

We waited an entire day to pick the leaves and prints up.

Step 6: Remove the Leaves, Enjoy & Admire

As stated in the previous step, we waited just about 24-hours to pick up our leaves and solar prints.

My children had a good time discovering what the print looked like underneath each of the systems.

The glass system left a small edge print around it where it fell on the paper, but that was barely visible.

The sheet protector and frame system left black where the frame was located on the paper. It was a neat effect, especially if I was going to frame these prints in a larger frame. That could definitely be something to consider if one is making these types of prints to use in a card of some sort.

The last system with the rocks also worked, although as expected, the edges of the leaf were not as pronounced as with the other methods.

My children were all happy and proud of the results and that was all that mattered.

Another elective checked off for those Cub Scout requirements and another hour or so spent with my children having fun while they learn. It's always a win-win!