Chromatography butterfly craft

Last year we tried chromatography with felt tip pens.  My then 2 year old wasn't really interested, it was too slow and conceptually difficult to work out why some of the felt tip inks were actually mixtures of colours.  Since then, we've done lots more colour mixing activities and he's become familiar with the idea that you can make a colour by mixing combinations of others.  I thought it might therefore be fun to revisit the chromatography experiment, and this time I made it quicker, less structured and added a craft element to see if it would hold his interest.

Drawing dots on folded kitchen roll

We started off with some kitchen roll which was more absorbent than the paper we used last year.  This means the water, and coloured inks, travel faster up the paper so you see results faster.  It gives a less crisp colour separation, but I decided speed was more important!  We used Crayola washable felt tips for this, you need pens with water-soluble inks.

Symmetrical pattern

My intention was to make a butterfly shape with the resulting chromatography, and as butterflies are symmetrical I folded the kitchen roll in half so that we would create the same pattern on each side.  To do a proper experiment to find out which colour dyes were in each pen, you'd need to put dots of each pen at the same height above the water so you could compare how far the different ink colours travelled.  I decided, based on last year's experience, that this was probably going to end in frustration so i said to my son he could put dots of whichever colours he liked on the kitchen roll, trying to keep them towards the central fold.  I asked him to hold the pen on the paper long enough for the ink to soak through the paper to the other side - he tried a few times and decided that he needed to count to three each time whilst he held the pen down to make sure there was a big dot on both sides.

Colours moving upwards, carried by water

Once he was happy with his artwork, he unfolded the paper to have a look at the symmetrical pattern.  Then we folded it back up and rolled it into a tube such that the fold line was at the bottom, and secured it with a paperclip.  We then put it in an empty large yoghurt pot with about 1cm of water at the bottom.

Colours have spread out up the paper

The inks started to travel rapidly up the paper, and my son was quite enthralled.  He noticed that the brown and black pens didn't stay brown and black, but different colours started to appear, with blue dye moving more slowly up the paper than other colours as the water rose up the paper due to capillary action.  He watched it for a few minutes then wandered away.  

Cutting out legs

After about 10 minutes, the water line was nearly at the top and we took the paper out and carefully slid the paperclip off the paper.  We had a look at the different colours and how far they'd travelled then pegged the soggy paper on the washing line to dry.

Some of the colours on the paper washed out into the water in the pot - if you put the colours slightly higher up the paper such that the water level doesn't reach them you avoid this and get a more vibrantly coloured result.  I also think the colours faded as it dried on the washing line, it was a very sunny day and we forgot about it for a few hours.  As it was, my son was pleased with what he'd made, but it wasn't as brightly coloured as I'd hoped it might be. 

Finished butterfly

My son is usually averse to art and craft activities, but having had a revelation the other day that the reason he hates trying to cut anything is that his totally blunt children's scissors are safe but absolutely useless for cutting, I ordered him some which are sharp (but have a rounded end, they are aimed at age 4 and upwards).  He had a go with them and it turns out he's actually pretty good at cutting out things and he enjoyed doing it with a tool which actually worked.  I thought a craft activity that involved a bit of cutting might therefore be fun, so together we made a butterfly with the chromatography.  He wasn't totally keen so I cut the wings and the body of the butterfly and asked him to do some legs which he was happy to do.  We then stuck them with PVA glue together.  It was a nice opportunity to talk about insects having six legs again which recapped an activity we'd done on numbers of legs different creatures have a few weeks ago.  He liked his butterfly briefly but rapidly lost interest in it, so I'm not really sure if turning it into a craft activity was a success but he was more engaged in the whole process than in last year's chromatography.