The Epson Problem for Multicoloured Pens

How might we replace the ink of one colour without buying a new multi-coloured pen?

The year was 2000, and I was invited by my school, Singapore Polytechnic, to join an "Entrepreneurship" programme they called "Product & Process Engineering" course. It would be an additional course we voluntarily enrol, but were invited to by virtue of being the top 5% in the Year 1 cohort.

The course consists of weekend Saturday lectures about Product Development, which we would do alongside our Diploma. Upon completion, we would be awarded a Certificate in Product and Process Engineering.

At the end of the course, we were supposed to come up with a prototype of the product we decided on building, and a short pitch to judges in order to win S$1,000. A lot of money for a teenager.

We were split into teams of 10, and we had to come up with ideas on a product we could build. During that brainstorming process, I came up with just 1 idea, that had a complete problem statement, and a working sketch all in 30 minutes. Bear in mind, at the time I hadn't realised I was a good product designer. I was a Diploma in IT student. I thought I would be a software engineer. I wasn't good in art, which was what I thought you'd need to become a product designer. Turns out I was wrong. A designer and an artist are quite different.

The problem statement that I worked on was "How can we get rid of the pencil case altogether?" I didn't use a pencil case because I was an IT student. I envisioned a life without writing anything. (Turns out I was wrong too). So I only needed a few pens and a tape eraser. But there were too many pens which meant I still needed a pencil case. 

A solution for too many pens already existed. The Quatro, or multi-coloured pen, was just like any spring action pen except that it contained 4 to 6 different colours. You clicked on blue, and the blue pen tip would appear. You clicked on black, and the blue retracts and the black pen tip would appear.

There was just one problem. You'd end up running out of blue ink faster than you would the black or red or green. Which meant, you kept a spare single ink blue pen, or you buy a whole new Quatro.

I toyed around with a few sketches and took inspiration from a stackable pencil I used to buy in primary school.

These were disposable pencil tips which kept its overall shape. When one tip runs out, you just remove that tip, and the one stacked under it appears. This was a time before the mechanical pencil, but it was great! It meant, I didn't need a pencil sharpener and when I ran out of lead, I bought a whole new stack.

So what if you could replace the blue ink without buying a whole new Quatro?