Fun science experiments for kids with Letterbox Lab

Fun science experiments for kids with Letterbox Lab

STEM and STEAM are all the rage in schools these days.  (STEM aka Science, Technology, Engineering, Mathematics and STEAM as Science, Technology, Engineering, Art, Mathematics).  In recent years, fewer students have been taking up STEM subjects at university and college, and far fewer girls in particular.  I worked in education marketing for nearly 11 years and helped develop many fabulous STEM and STEAM resources for schools to encourage more interest at an early age.  Flora loves all things engineering (well, taking things apart anyway) so she was hugely enthusiastic when Letterbox Lab * asked if she’d like to try one of their kids science subscription boxes.  What did she think?

Letterbox Lab

We’ve enjoyed quite a few kids subscription boxes since I started blogging but this is our first science one.  Letterbox Lab is a series of 12 science kits with full instructions, and all of the activities are linked together as a story rather than as a theme.  Online resources accompany every box with a how-to video (should you need it) as well as suggestions for further experiments and activities.  There are two different versions of Letterbox Lab: the Explore box (for age 6+) and the Investigate box (for age 8+).  Both support the primary school curricula of all four regions of the UK, and one off boxes start at £11.00 including P&P.

Hidden Rainbows

We were sent the first in the Explore series – so what was inside our Hidden Rainbows box?  Hint: kit for three different types of experiments.


  • Incredible Inks – including felt tips, chromatography paper, petri dish, smarties, 2 x bottles of salt, 2 x dropper tips, scissors
  • Rainbow Glasses – glasses frames, scissors, diffraction grating, 8 x glue dots
  • Rainbow Spinners – round discs on cardboard, scissors, pencil, spinning top
  • An instruction booklet, a safety sheet, and an Eager Explorer sticker.

Incredible Inks

These experiments were all about discovering that different coloured inks are made up of different colours mixed together.  Flora drew a black line on a strip of chromatography paper (special paper that can separate mixtures) and then put the end of the paper into some salty water.


As the water travelled up the strip, the colours that make up black began to reveal themselves, mainly red and blue in this case.  She then tried lots of different colours before coming to the conclusion that dark colours produced better results.


Next, she put some fresh water (no salt) in a petri dish along with a green smartie.  After a few minutes, all the dye had come off and she had to test to see if the dye would come up another strip of chromatography paper.  It didn’t really work but she got to eat the sweets anyway, so a happy girl.


For the last experiment, Flora had to draw something on chromatography paper first and then see what happened when she dripped salty water on it.  We were both rather wowed by the resulting artwork!


Rainbow Glasses

These were very straightforward: once she’d coloured in the frames she had to stick the diffraction grating on (for lenses) and then model them.  Ta-da – basically looking through prisms for a rainbow effect!  From a science point of view, it was about discovering that white light is actually a mix of all the colours of the rainbow.


Rainbow Spinners

We had to cut out the three coloured discs and alternate them on the spinning top.  I have to say, it was very hard to use the spinning top, perhaps a larger nub on the bottom would have made it easier.  But what we discovered was that cyan, magenta, and yellow mixed reflected light to make white.  And that faint coloured rings appeared when we spun the black and white disc.  Nothing spectacular happened with Flora’s coloured in rainbow disc but it looked pretty 🙂


Final thoughts

Flora absolutely LOVED this box.  So much so that she decided to create her own scrapbook for this first box, with everything that’s possible to stick in, stuck in.  I’ve never seen that level of enthusiasm from her for anything like this before, so I’d say Letterbox Lab is a big hit.


The Explore Hidden Rainbow activities took us about two hours on a rainy Saturday morning, and time certainly flew by while we were having fun.  Big thank you to Letterbox Lab for letting us try this one.  As Flora’s eight and half, I think if when we get the second box in the series, we should opt for the Investigate box because it has more extension activities for older children.  As Albert Einstein said, “Play is the highest form of research.”  Who would have guessed salty water could provide so much fun!

* We were gifted this box in exchange for a review but all opinions are our own and this is an honest, unbiased review.



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Cordelia Moor

This is so cool! I love that companies are putting out these kind of boxes now, I wish that there had been more of an emphasis on how science can be fun when I was at school, because it’s only recently I realised it isn’t all that boring – and I wish I’d paid more attention. And what more can you ask for than when your kid has so much fun they go and make a scrapbook about it?!

Cordelia ||

Creative Nails

Wow, this is so cool! I wish stuff like this was more available when I was younger. I remember my dad used to always try and look out for interesting things like this for us to do. It’s always so cool to find out that you used to work in education marketing for 11 years! I am currently doing a digital marketing apprenticeship for a school, although I work on their website and social media, I do see quite often things going on – they quite often have a STEAM week and have different activities planned! I’m so glad to… Read more »

what corinne did

I love science! and that sort of box would have made me so happy as a kid! It is so creative and cool!

andthenzen ✨

Oh my word, I would’ve loved this when I was Flora’s age, chromotography was always one of my favourite things to do at school.. 🙊 The artwork she created was incredible as well, a gorgeous piece of work! ✨


Oh my gosh this is amazing! My niece would absolutely love this!

Love, Amie ❤
The Curvaceous Vegan


Ooh this looks so much fun. Doesn’t have to just be for kids right? Hehe! Great post!


This is so cool! It shows kids that science can be fun and it’s a great way to explore it 🙂

Sophie Bolton

I’m 24 but I think I would enjoy this!
Sophie x


Oh wow I love that Letterbox Lab have chosen a rainbow theme and included such colourful experiments! It looks like Flora had so much fun with all of these and I think even girls less interested in engineering would have fun with it! If If more of my science lessons included Smarties I’d have definitely been more interested haha

Soph – x


This seems like something my youngest would love to do! Shes big on anything color related lately!


Awwww my little brother would love this!


It’s so cute that she created a scrapbook about it! I was never a huge fan of science at school but the times we got to play with things like chromatography paper were always fun. I’m glad she enjoyed it! I think it’s about time she had her own little category in your menu. I always love reading about the things she’s trying/ making x


Chloe Dickenson

I’m so glad that Flora enjoyed this box, it sounds absolutely fab for kids and is definitely something I would have loved as a child! xx

Eve Morgan

This Science kit looks so fun! My little cousin would love this! I think these boxes are a great way to trick kids into learning through crafts and fun activities. Flora looked like she really enjoyed it!

Eve x


This is fantastic! I’ve never been interested in science, but I think this would have been enough to reel me in. What an awesome, original way to teach kids about science and have some fun. I love the name of it, too, how did no one think of this sooner?! Thanks for sharing, Lisa.


What a lovely and interesting concept. My daughter would’ve loved all this a few years ago, she’s 13 now but I’m pretty sure she would love those rainbow glasses. Lovely post!

Samantha x

Nikki - Notes of Life

This looks like such fun! I think my niece and my nephew would love it 🙂

Jenny in Neverland

Nevermind for kids, this is something I’d absolutely love to do myself haha! I bet Flora had a great time doing all of these 🙂


There seems to be a subscription box for everything now!

I love that this one is educational for kids though.. there was nothing like this when I was a kid! Although, I had this one science kit in a box (but I wasn’t allowed to use it because it would make too much mess!) I used to take out all the little bits and imagine actually trying them out.. haha. So funny how I received it as a gift and wasn’t allowed to use it. I’m glad to see you’re not worried about any mess.

Thanks for sharing! ♥

Ellis Woolley

I had my mouth wide open whilst reading this entire post because it’s so AMAZING to see a subscription box aimed at children that is science based! I’m SO impressed with this brand just from reading about your experience that I’d love to give it a go myself, I used to love mucking about with chromatography paper and you explained everything so beautifully 🙂 Ellis x x


Wow, this is such a cool subscription box! I love everything from the name (Letterbox Lab is brilliant!), the bright and eye-catching design on the box, to the fun and interesting scientific experiments. The artwork on the chromatography paper is awesome, how colourful! Great job Flora! I would actually love to give that a try myself, he he. I wish these kinda boxes were available when I was growing up, I’ve always been fascinated with science. I love that this kit is a combination of both science and art, it seems like such a fantastic way for young people to… Read more »

Via Singh

Hi Lisa! You always have some amazing and intelligent boxes for kids. This one again is so interesting and the kids will really enjoy. I like the idea of play and learn. You were in the education field for 11 years, now that is amazing too. Love the pictures my dear. 🙂

Via |


I love that I’m seeing more and more of these subscription boxes! It’s such a cool idea and a fun monthly thing for the kids to look forward to. Such a fun thing to start with your kids!


This looks like a great subscription box and something I would have enjoyed myself as a kid. Great review Lisa.

Alice v

That’s amazing that she was inspired to make her own box. This sounds like a lot of fun. My kids love science too.