b. 1986, HK.

We are book, game, and font designers specializing in educational picture books for children. We’re best known for “Mapy”, “Mamoko” series, and “S.E.R.I.E.S.”. We also enjoy knitting, playing video games and board games, watching TV shows (with X-Files at the top of our list), not to mention collecting picture books, comic books, and graphic novels.

For inquiries about the available foreign rights to our books, please contact Jadwiga Jędryas from Dwie Siostry Publishing House.



We were both born in 1982, with a difference of only 2 days between each other. We met in 2002 during Academy of Fine Art in Warsaw entrance exams. We studied at the Faculty of Graphic Arts, had the same teachers, did the same exercises, we both graduated in 2007 in Maciej Buszewicz’s Book Design Studio and had similar ideas about what we wanted to do.

At the end of our third year of studies we started taking commissions for graphic design projects and we established Hipopotam Studio. We specialized in book design and quite specific website designs. We used Adobe Flash technology and were building sites that were dense with animation, sounds and videos. It was a great time for rich, surprising, and fun online experiences. If you still have Adobe Flash on your computer, you can see some of our websites on hipopotamstudio.pl (or you can dive even deeper to our older website here). Few games (like Bubole or Pica Pic) can also be seen in the Games and Stuff section.

Print design was another thing. We had lots of small commissions for posters, leaflets, catalogues and other commercial products in the art and small business sectors. We also have few book covers and book series designs under our belt.

Just after graduating, we created a set of books that were never published (you can see them in the Beginnings section). We showed them to potential publishers in hope of getting a commission for our first book. Most of them were reluctant, but Wydawnictwo Dwie Siostry asked us to create a book about modern architecture. This was our debut and the beginning of a long cooperation with Dwie Siostry.

Back then, making picture books for adults in Poland was not an option. Fortunately, it was an extremely good moment to create books for children. After the ‘60s, ‘70s, and ‘80s, which were the golden decades for book design in Poland, in the ‘90s one could witness the total collapse of good design in general. Old, big publishers couldn’t handle capitalism and the market was flooded with the worst picture books from western countries. Cheaply produced, without any valuable content and not a trace of taste or even basic designing skills.

At first, readers didn’t react to such a dramatic fall. Our country was still rebuilding after years of Communism and people had bigger problems then ugly picture books. In the early 2000s some small publishing houses started popping around. One of them was Wydawnictwo Dwie Siostry.

Dwie Siostry after just few years have grown to be the best and the most recognizable publisher specializing in children’s literature. We are proud to be a part of their legacy and one of the many reasons of their success.

What’s going on with your names?

In Polish language first names are often shortened in an irregular way. Aleksandra is one of the most popular name in Poland, but on a day-to-day basis almost no one uses the full name. The shortened version is “Ola”… Not even “Ala”, just “Ola”. This causes a lot of confusion among our foreign friends (especially in Spain).

The second oddity of Polish language is that the surnames have alterations that may vary depending on gender and plurality. So Aleksandra is Mizielińska, Daniel is Mizieliński, and together we are Mizielińscy.

The last thing is pronunciation, not the easiest one for foreigners. You can listen to Daniel pronouncing our names below.


Since 2008, Daniel is teaching at the Graphic Faculty at the Academy of Fine Art in Warsaw. At first he was an assistant at Maciej Buszewicz’s Book Design Studio, but since 2012 he started developing his own program around screen design. For the first two years it was concentrated on web and app design, then it shifted to games, and now it combines games and comic books.

This strange path follows the needs and capabilities of students. The Academy attracts specific people and the syllabus should not be set in stone. Fortunately, Academy gives the opportunity to assign different task to each student and work individually on their specific design challenges.

Aside from academic endeavors, we created kursownik.pl – a website with online courses covering software and some skills necessary for anyone who wants to be a designer. The site was created for Daniel’s students, but we decided to open it for everybody. It’s totally free. There are no ads, no fees, and no private data selling or even data analyzing. The only data we collect is for users benefit only (like the ability to track one’s progress after singing in). Even the users emails are crypted, so we can’t even send emails to anybody.