This fun chromatography craft for kids is ideal for those ‘I’m bored’ moments over the summer holidays or if you’re stuck inside on a rainy day and are looking for indoor activities for kids. Through making these simple colourful paper flowers using coffee filters and washable markers, children also get to practise fine motor skills, so gather up a few supplies from around your home and let’s get started!
What is chromatography?
Chromatography is the science of separating mixtures, which are in gas or liquid form, by letting them climb slowly past another substance, which is typically a liquid or solid. With the washable markers and coffee filter trick, we have a liquid (the washable ink) dissolving in water climbing over the surface of a solid (the coffee filter paper). Capillary action makes the water travel up the coffee filter paper where it meets and dissolves the ink, and the dissolved ink slowly travels up the paper. Scientists use chromatography techniques in labs to observe mixtures and solvents when testing food and drinks, forensic testing and even developing vaccines. Pretty cool!
- Washable markers
- Coffee filters
- Cups of water
- Paper plates and kitchen roll
Do this activity:
Place a paper plate on a table and a coffee filter on top (this is to avoid the marker ink seeping through onto the table surface). Choose one marker or more per coffee filter. Because your child will be dipping the centre of the filter in water, encourage your child to draw a circle around the edge of the fold where the crease meets the centre. There are no rules on where to colour so let your child get creative because part of the STEAM (Science, Technology, Engineering, Art and Maths) process is letting young minds adventure through the materials given to them at hand.
Fold the coffee filter in half, a quarter, an eight and a sixteenth (you just worked in a quick lesson on fractions!).
Dip the tip of the cone into water and allow the filter to absorb water and watch as it flows up the paper. Avoid immersing the filter as it needs to be damp enough for the colour to run upwards, but if it gets too wet, the filter will go soggy. Try this with different colours – your child could even mix colours.
Once the colour has seeped up to the outer edges of the filter, carefully flatten the filters and place those on a sheet of kitchen roll to dry.
Make the flowers
Once dry, pinch together the centre of the filter to bunch up the filter into a flower shape. (PS. This action doubles as a fine motor skills activity.)
Secure the flower to a straw using a piece of tape. Pop in a vase for everyone to see!
Tip: For another quick and easy chromatography science experiment idea for kids, watch TheDadLab’s video on how to make art with science using kitchen roll and washable markers.