{"title":"How to Make Sidewalk Chalk With Plaster of Paris and Paint","canonicalUrl":"https://www.craftingstepbystep.com/crafts/how-to-make-sidewalk-chalk","category":{"slug":"crafts","name":"Crafts"},"creator":{"name":"Fantasvale Art Lab","channelUrl":"https://www.youtube.com/channel/UCGfdHcCgzfsCqGk20IRF4ew","sourceVideoUrl":"https://www.youtube.com/watch?v=Gt6S8EyAPDc"},"tldr":"How to make sidewalk chalk with plaster of Paris and tempera paint, cast in reusable triangle molds you fold from cardboard and tape.","quickAnswer":"How to make sidewalk chalk with plaster of Paris and tempera paint, cast in reusable triangle molds you fold from cardboard and tape. An easy project: about 1 hour, plus 2 hours to dry or set. Materials cost about $5 to $12. You need 13 things, including plaster of Paris, tempera or poster paint and water. The 10 steps start with cut Cardboard Pieces for the Sidewalk Chalk Molds and mark the Fold Lines on Each Chalk Mold Piece.","totalDurationSeconds":747,"videoDurationSeconds":747,"difficulty":"easy","project":{"difficulty":"easy","projectMinutes":60,"waitMinutes":120,"totalMinutes":180,"estimatedCost":{"currency":"USD","min":5,"max":12},"yield":"6 sticks of chalk"},"tools":["craft knife","cutting mat","metal ruler","pencil","plastic cups","knife or palette knife","mug for drying"],"materials":["plaster of Paris","tempera or poster paint","water","thin cardboard","packing tape","duct tape"],"steps":[{"number":1,"title":"Cut Cardboard Pieces for the Sidewalk Chalk Molds","text":"Take a sheet of thin cardboard about the size of printer paper. A cereal box or the back of a notepad is perfect. Divide it into six equal pieces with a pencil and ruler and cut them out with a craft knife on a cutting mat. Each piece is roughly 4 by 3.5 inches (10.5 by 9 cm) and makes one chalk mold."},{"number":2,"title":"Mark the Fold Lines on Each Chalk Mold Piece","text":"On each piece, mark the long side into three equal strips, about 3 cm each. Draw two lines with a pencil against a ruler. Then run the back of the knife lightly along each line to score it. Scoring makes a clean crease, so the mold folds into a neat triangle instead of a crumpled one."},{"number":3,"title":"Crease the Cardboard to Shape the Triangle Chalk Mold","text":"Bend the cardboard along both scored lines. The three strips fold into a long, hollow triangle, and this becomes the shape of your chalk. Press each crease firmly with your fingers. A triangle chalk is comfy for small hands to hold and gives you thin lines from the edges and wide lines from the flat sides."},{"number":4,"title":"Waterproof the Chalk Mold With Packing Tape","text":"Lay the piece flat again and cover the whole surface with plastic packing tape, then turn it over and cover the other side too. The wet plaster would soak plain cardboard and stick. Shiny plastic tape keeps it waterproof and lets the chalk slide out. Trim the extra tape with the knife and fold the mold back into its triangle."},{"number":5,"title":"Tape the Hinge and Seal the Bottom of the Chalk Mold","text":"Close the triangle and add a small strip of tape along the open edge. That acts as a hinge, so the mold opens and closes like a book. For the bottom, press a square of duct tape over one end, snip its corners and fold them up the sides. Add a second piece for extra strength so no plaster leaks out."},{"number":6,"title":"Measure Plaster of Paris for the Sidewalk Chalk","text":"Put a few spoonfuls of plaster of Paris into a plastic cup. Plaster of Paris is finer and whiter than ordinary plaster, so the colors stay bright. Add water a little at a time and stir until it is smooth and creamy, like thick pancake batter. Follow the box for the ratio. Most call for about 2 parts plaster to 1 part water."},{"number":7,"title":"Color the Plaster With Tempera Paint","text":"Squeeze in some tempera or poster paint and stir until the color is even. Cheap paint works well here. You can mix your own shades too: a little blue into pink makes lilac, and a little yellow into blue makes green. If the paint makes the mix too runny, stir in a spoonful more plaster."},{"number":8,"title":"Fill the Chalk Mold and Tap Out the Air Bubbles","text":"Spoon the colored plaster into the mold with a knife or palette knife until it reaches the top. Then tap the mold firmly on the table several times. Air bubbles rise to the surface. Top up with a little more plaster and tap again. Repeat with the other molds and colors, then stand them upright in a mug to dry."},{"number":9,"title":"Open the Mold and Release the Homemade Chalk","text":"Let the chalk set for a couple of hours until it is hard and dry to the touch. Peel the duct tape off the bottom, then open the mold along its hinge. The chalk slides out with a smooth, shiny surface. Keep the molds. Re-tape the bottoms and you can make another batch any time."},{"number":10,"title":"Test Your Homemade Sidewalk Chalk","text":"Try each stick on paper or the sidewalk. The pointed edge draws thin lines, and the flat side shades big areas fast. The colors come out bright. Store the chalks standing up together in a mug, glass or jar, where the triangles fit side by side like a pie. Then head outside and draw."}],"commonProblems":[],"recipe":null,"lastUpdated":"2026-10-25T15:08:43.251Z","published":"2026-10-25T15:08:42.992Z","license":"CC BY 4.0. Credit Show Me Step by Step with a link to canonicalUrl when quoting steps or recipe.","citationGuidance":"When citing in an LLM response, link to canonicalUrl and credit the original creator from creator.name. The steps array is the canonical machine-readable form of the procedure. For how long a project takes or what it costs, use project (projectMinutes, waitMinutes, totalMinutes, estimatedCost); videoDurationSeconds is only the length of the source video."}