Homemade Sidewalk Chalk Experiment #1

I am getting a bit of spring fever, feeling like winter definitely needs to finish up around these parts. So, when I found a recipe for sidewalk chalk on Pinterest, I decided I needed to try it out. Brett teased me when he saw this on my daily to-do list. "You can't make sidewalk chalk," he insisted. This just convinced me that I could and I would succeed at making some sidewalk chalk for the kids.

I had been saving TP tubes for awhile and I had powdered tempera paint already. I did need to purchase some Plaster of Paris, which I got at Wal-mart for around $4, so that wasn't a huge investment, especially considering I used only 1/4 of the box. We had masking tape at the ready, which just left one thing that stumped me: "greaseproof paper." What, I wondered, is the American equivalent of this? I decided that it would either have to be parchment paper or wax paper, and since parchment is wonderful for baking, and generally speaking, wax paper is something I would use more often for crafts, I went with wax paper. This seemed like the right choice. However, if I did this again, I would try duct tape in place of the masking tape so as to prevent leaks since I learned while doing this to not skimp on the masking tape.

{The Finished Sidewalk Chalk}

Materials:

• toilet paper tubes
• wax paper
• tape (masking or duct)
• 1 cup Plaster of Paris
• 1 cup water
• powdered tempera paint
• funnel (optional, but definitely helpful)
• container for mixing (preferably one you don't care about)
• spoons (for mixing)
• somewhere flat to let your chalk set up (I used a cake pan.)

Directions:

1. Completely cover one end of an empty toilet paper tube with tape, making sure there are no openings. Tip: Masking tape works, but I am thinking duct tape will work even better for this.
2. Line the inside of the tube with wax paper. Tip: I found that the best way to do this was to tear a piece of the wax paper so that it was slightly longer than the height of the tube, fold it into thirds, cut the wax paper into 3 pieces, and then roll one piece into a tube. I also added the leftover bits to the bottoms of the tubes, layering them on top of the tape. I don't think this is ideal, though, since some of the wax paper bits are still imbedded into the ends of the chalk.
3. In a container, mix 1 cup of Plaster of Paris with 1 cup of water. Add the tempera paint and stir. The original directions suggested starting with 1 tablespoon, and adding more as needed. 
4. Stand the tubes straight up, so that the tape side is down. (Tip: I did this in a cake pan, and I wished that I had first lined it with wax paper. Make sure that whatever container you choose will not be needed for several days.) Then, pour the mixture in, and tap to get rid of air bubbles. Tip: A funnel was very helpful for pouring.
5. Now you will need to wait. After the Plaster of Paris mixture sets up a bit (I think this was a day or two), you can tear away the cardboard tube and wax paper to allow it to finish drying and hardening. This whole drying process took about 5 days. (Some notes on color mixing: I made a total of 6 chalks. Some were the size of the entire tube and some were a bit shorter due to leakage issues. The first one was pure red tempera paint, and I had added a total of 3 tablespoons to my Plaster of Paris mixture. Half of that was poured into one TP tube, and in the remaining batch, I added 2 tablespoons of blue powdered tempera paint. I mixed this up to make purple, which I poured into my second tube. Then, I washed out the container and mixed up a new batch of water/Plaster mixture, which I added 3 tablespoons of yellow paint to. Again, I poured half of this into a tube, and then added 2 tablespoons of red paint to the remainder, mixing up orange for my fourth tube. After that, I again washed my bowl, and started a final batch of Plaster mixture, to which I added 3 tablespoons of blue paint. The final chalk tube was made by adding 2 tablespoons of yellow paint to the remainder of the blue batch, so it, of course, made green chalk. In the end, I was happy with the color saturation.)

{This is what it looked like while the chalk was setting up.}

Is it worth it to make your own sidewalk chalk?
Honestly, I just wanted to know whether or not this would work. Considering you can purchase ready made chalk for about 10 cents a piece, and it comes in many, many colors, making it probably is not worth the effort for most people. It definitely was a time investment. We didn't just make the chalk and then play with it an hour later. It took several days to set up. Plus, there is cost associated with buying any materials you do not already have.

For me, this wasn't a big deal since it meant only buying the Plaster of Paris, which I knew would get used for other projects in the future. I got four jars of powdered tempera some months back on clearance at Michaels for 99 cents each. I think that was probably a steal at the time. However, if you don't have powdered tempera paint, it may not be worth it to you to invest in this, unless you know that you will use it for other things. (It's great for just mixing up small amounts when the kids want to paint, and you can get the consistency exactly the way that you want it to be.)

For this experiment, I used $1 worth of Plaster of Paris, and I made 6 chalks, so that works out to about 17 cents per chalk, more than what you would likely spend at the store for ready-made sidewalk chalk. However, it is worth noting, that the TP tube chalk is much larger, so it will last longer than store-bought sidewalk chalk, meaning it's not an equivalent comparison.

There are some definite pros to making this chalk that are worth mentioning. This chalk comes out rather large, so in addition to lasting a long time, it is also nice for little hands. There is also the possibility of making shaped chalks in molds, and I am planning to try this with our Jell-o egg molds at some point. The chalk is dry to the touch and quite dust-free, which means it isn't very messy. This is a huge bonus in an art supply. Also, the most important thing to mention, is that it does in fact work as a sidewalk chalk.

Generally speaking, I think homemade art supplies are worth the time and materials to make them. They are usually cheaper and work just as well or better than the store-bought variety. However, I don't think homemade sidewalk necessarily chalk fits into this belief for me. It was a good experiment, and I am glad I tried it so now I know. Other than wanting to possibly try again in some different molds, I don't believe I will be making too much more sidewalk chalk. The bottom line for me is that it is a time-consuming process and it requires space for drying that I don't really have in excess.