In the 16th century, ink was made with either carbon ink recipes of iron gall ink recipes for basic writing of letters or the average penmanship. Blue and red did exist, however, and this week, we are going to explore how to make red ink from blue ink using a recipe written in 1594 by Sir Hugh Plat in his book, The Jewel House of Art and Nature.

As you can tell from the many portraits and paintings from the time period, or even the elaborate drawings inside publications like the Paston Letters, a wide variety of other colors existed as well. 

Two that were popular for scribes were blue ink and red ink, which while rare in terms of their wide usage, were common enough that Sir Hugh Plat, who is famous for writing 16th how to manuals for the average household, including a fun little experiment that helps kill two birds with one stone, or in this case–two inks with one pen. 


Hello there, I’m Cassidy Cash, I am host of That Shakespeare Life, and every Saturday I share with you a small snippet from the life of William Shakespeare. This week we are exploring a fun experiment from a 16th century household manual written by Sir Hugh PLat that shows you how to write with Blue and Red ink at the same time. This experiment can be completed at home with items you either already have or can easily acquire, so let’s get started.

Excerpt from pg. 63 of The Jewel House of Art and Nature by Hugh Plat (1594) describing how to turn blue ink red using “hazel nut of litmus blewe”. This document is available in the public domain and I will send you a full pdf of the entire book when you sign up for my newsletter using this form:

If you’re new here, please hit like and subscribe for more videos just like this one

In his book, The Jewel House of Art and Nature, published in 1594 (the same year the Lord Chamberlain’s Company was formed), Sir Hugh Plat wrote a series of household advice including how to hold a hot iron with your bare hand, how to fatten up a horse for riding on long journeys and dozens of other small tricks of the trade that make life easier and more efficient at home. One that is particularly interesting and that we are going to cover today is the one paragraph instructions Hugh gives for writing with blue and red ink, when all you have is blue ink. He calls it “How to write both blew and redde letters at once, with one self same inke and pen, and upon the same paper” 

The experiment he outlines works a lot like the kits you may have gotten as a kid which has you writing with invisible ink. In this case, lemon juice is used as the invisible ink and the blue ink covers it up “revealing” the red ink. The natural base for the blue ink in Hugh’s recipe creates a chemical reaction with the acidic lemon juice, and creates red ink.


Here’s how you can do it too! (Download a printable version of these instructions here)

Start with some blank paper. The lemon juice does bleed through regular printer paper, so you may want to use something thicker like watercolor paper, but as I am not going to be hanging this up anywhere, printer paper worked just fine for me. I do not recommend lined notebook paper, however, since those pages already contain ink and could mess up your colors. 

First we want to prep our ink. I tried watercolor blue paint, as well as a blue sharpie first and that does not work. It appears that what hugh calls “Hazel nut of litmus blue” is a natural based ink that seems to be neccessary to get the ink to turn red with lemon juice. 

I looked up hazel nut inks and I am unable to find a 16th century ink recipe that calls for hazelnuts. I found some ink recipes that use walnut oil, but in general for Shakespeare’s lifetmie, inks and especialyl inks made at home were crafted using what one had available and consisting of only a few staple ingredients that could be interchanged, much like you can subsitute grapeseed oil for most instances of canola oil in cooking recipes today, so I imagine the recipes for ink worked for SHakespear’s lifetime and that might explain the reference to hazel nut oil in this manual. 

Not having hazelnut ink on hand in my kitchen, however, I decided to use my own concoction of ink based on historical recipes that indicated berries could be used to make pigments ink (there aer some sources for how I came to this conclusion in the show notes) 

So I had some frozen blueberries. I warmed them up and smashed them in a cup, and mixed the blue berrie juice with the gum arabic and conduit water Hugh plat recommends in this manual, only I used tapioca starch as my gum arabic substitute and tap water since I do not have a conduit nearby. 

Mixing all of this together and allowing it to sit for several minutes (you will want it to sit for one full hour to properly follow hugh’s advice), it does indeed paint blue on the page! 

Now having my blue ink ready and a sample square set out on the page for comparison, I used pre-juiced but 100% juice lemon juice and painted a square of that onto the page. It goes on invisible like Hugh Platy says it will, and I left it to dry, as his recipe indicates that is important. 

While waiting on the lemon juice test square to dry, I wrote out Shakespeare in lemon juice to see if we can get that to change colors, and allowed that to dry as well. 

Once the lemon juice was sufficiently dry (about 15 minutes), I painted over it with the blue ink. At first, it goes on blue and you think nothing is happening, but then after about 10 minutes everywhere the lemon juice is interacting with the ink starts to turn pink. What do you know! A nearly 500 year old recipe for writing with two color inks at once really works.

That’s it for this week! Thank you for being here. If you like experiments like this one which let you try out a piece of the life of William Shakespeare, consider joining us inside That Shakespeare Life membership. Each month I send you an activity like this one that you can do at home to learn something new about the life of William Shakespeare. Learn more and sign up now at

I’m Cassidy Cash, and I hope you learn something new about the bard. I’ll see you next week! Bye!

Sources and Resources: