Blaž Urban Gracar

Blaž Urban Gracar is a Slovenian artist. He is a musician (composing music for the theater, producing left-field electronica, playing keyboards in a rock band), writer (publishing poetry, prose and comic books), filmmaker (editing and animating short films), and game designer (mostly creating puzzly solo games). He lives by the sea with his partner, her daughter, two cats, a dog and a turtle.


Q. Hello, Blaž!

A. Hi, Puzzle Prime! Thanks for featuring me.

Q. I know you are quite a busy person, I’m glad to have you here.

A. Never too busy to talk with friends! But yes, my calendar has become quite crammed lately. I spend most of my days making music, which is basically my main source of income. I compose music for films and theater, but I also make strange electronic music and play keyboards in a rock band. Besides music and game-making, I also write – I have published a few books – and I make videos. Lately this means making animated shorts, but I graduated as a film editor, so I have made or collaborated on several films.

Q. Sounds great! I would first like to focus on your puzzles though, specifically your first published book, LOK. What was the inspiration behind it?

A. When I was making my previous puzzle book, Lineon, which is sadly still unfinished, I started corresponding with Stephen Lavelle, better known as Increpare, who made a bunch of great and acclaimed puzzle games, among them Stephen’s Sausage Roll, which is praised as one of the best puzzle games of all time. I sent him Lineon and he responded with a set of paper puzzles of his own, which were word-search puzzles using the Toki Pona language. Toki Pona is a constructed language that I don’t understand, so solving these puzzles felt very other-worldly. I started thinking how would such word-searches work if they used a completely made up set of words, which would have meaning only inside these puzzles. If we say “Apple” for example, we mean a red and round fruit. What if a word like “Lok” meant that you could erase a letter and that’s it? This idea felt very interesting to me and I quickly prototyped a puzzle which already used a lot of words that are present in the final book. It then took me about a year before I returned to this idea and saw potential for something greater.

Q. How long did it take you to finish LOK and what was the hardest part?

A. It took me a little more than 6 months to make LOK. I thought it would take me maybe 3 months, as I saw LOK as a smaller project at first, something to make in between bigger projects, so I pushed to finish it as soon as possible and made the first draft in about 2 months. I now see this as a smart approach – to rush the first draft – as it then took me 4 more months to perfect everything and make it really shine. I think it’s really important to have everything in place and see it for what it is, even if it’s not finely tuned yet. The last 10% were the hardest, but this was expected. It took me weeks to decide on some miniature details, like the correct font for titles, or the alignment of chapter artworks. Everything needed to match the vision, and it was hard to be certain what is correct in some aspects. But I’m very happy with how it all came together in the end.

Blaž making music

Q. How do you approach making a puzzle?

A. Well, apart from some rare tributes and try-outs of some already established genres, I generally like to make up my own system of rules, within which I then create a bunch of puzzles. I rarely do one-offs. So, when I first start exploring a new system I made up, I just throw things at the wall and see what sticks. These puzzles are usually ugly, random and without any real a-ha moments, but with them, I kind of expose most of what the system is capable of. I then re-do the puzzles that have interesting interactions or ideas, try to make them more elegant, guided and beautiful, but I also retain some of these early puzzles as they were, because they already work quite fine. So, after I internalize all the ins and outs of a system and start working on proper puzzles, my process is usually thinking of an idea that I would like the solver to find out and then kind of build a pathway for them. I try to think like the solver and how they would react to certain insights and deductions. Basically, I want the solver to have fun and to blow his mind every few puzzles, haha.

Q. How does creating puzzles differ from creating in these other fields?

A. Music, films, prose, all of these art forms are kind of direct compared to puzzle-making. They communicate something in a direct way, even if they are metaphorical or dream-like. Puzzles, on the other hand, work on two levels. One is the first impression: how they look at first sight, if they are symmetrical, big or small, if they intimidate or seem easy. The second level is the hidden meaning of a puzzle, its solution and how you get to it. It feels like designing an onion, where you want to put as many surprises into different layers as possible. You also need to be a lot kinder to the consumer of your puzzles compared to other art forms. You have to respect their intelligence and patience, make the system and a puzzle as mechanically sturdy as possible, because ultimately they need to “get” your message. You certainly need to be a lot more pragmatic.

Q. You come from Slovenia. Is there an active puzzle scene in Slovenia and do you hang out with other puzzle designers?

A. There is no puzzle scene in Slovenia that I know of. It’s strange, because ever since I got serious about game design, I feel like I create in a bubble. When I make music, people around me respond to it, they come to concerts, they buy CDs. Even my books, which are a bit more niche, find some audience in Slovenia. But my games or puzzles don’t really connect with anyone around me. It’s like I live a double life, one with friends and family, and the other just on the computer, which I use to communicate with puzzle lovers from around the world. This is how I got in touch with you as well. When I published LOK, I sold 95% of books to people outside of Slovenia, people I don’t know, people from Europe, America, Asia. It’s strange, but it also feels nice to at least have an audience somewhere, even for my small and weird little games.

Lineon Puzzle Book and Sountrack

Q. What are your next puzzle projects?

A. Based on the response for LOK, I already have many ideas for the continuation of the LOK story. The main one is the digital adaptation of LOK which I’m already working on with Raindrinker, a talented creator from Spain I met online. We hope to publish the game in 2023. Besides LOK, I might return to Lineon and start working on it again from the ground up, with the experience I gained in the meantime. There are some other ideas that I’m bouncing around in my head, maybe also a continuation of my solo card game “All Is Bomb” in some form. Let’s see what happens – I love designing games, so something will probably appear in a short while.

Q. Thanks you Blaž.

A. Thank you, Puzzle Prime!

Donald “Rusty” Rust

Donald “Rusty” Rust is an American artist who has created over 15000 paintings in a variety of styles. Even though he is famous mostly for his pin-up artwork, his optical illusions are some of our all-time favorites. In this special interview, he shares with us his thoughts on painting, op art, and everything which drives him forward in his long and successful career. If you like Rusty’s artwork, you can order some of it through his official store on Etsy.


Q. Hello Rusty. This is such an interesting nickname. I assume it is derived from your last name?

A. Having been born with red hair and having the name, Rust, made the nickname, “Rusty”, come easily!

Q. How did you get into painting? Was it a hard choice to devote your life to being an artist?

A. My painting career probably began one day when my grandfather, who was an artist, looked at a small drawing I had done. I must have been four or five years of age. He put me on his lap and took a drawing pencil, which he firmly pressed onto my drawing, showing me how to make my drawing more effective. Of course, that comes with confidence, something I did not yet have. My school years found me doing most of the posters within the school. After graduation, I learned that painting signs could supply enough income, so, that went on until I was about forty-nine years old. Then, I began doing portraits, which eventually led to other subject matter. No more sign painting!

Q. Apart from your grandfather, which other famous artists have inspired and influenced you?

A. Well-known pinup artist, Gil Elvgren, did work I admired. His guidance and help played a big part in the quality of my work. Bobby Toombs, Gil’s apprentice, also offered a great deal of help.

Q. Art trends have been changing a lot throughout the years. What do you think of contemporary art and how do you compare it with the more traditional art forms?

A. Times change and I welcome new ideas and styles of painting. Years ago, artists did not have projectors, air-brushes and digital images that could be altered with a click of a mouse. Always interesting!

Ambiguous optical illusion by Donald Rust

Q. You have been creating all kinds of compositions – pin-up girls, landscapes, portraits, illusions… What is the reason to be so versatile and what type of work are you currently focused on?

A. I’ve been versatile, mainly because I continually look for subject matter that “catches on”. Everything I tried provided a variety. My studies were geared primarily toward realistic painting. Over the years, my interests have changed. Now, I am doing more fantasy-type work, which allows for more creativity and originality.

Q. What is your secret for creating such amazing optical illusions? Do you first start with the hidden image and then try to conceal it, or first draw the main picture and then incorporate the illusion inside?

A. I have no formula for the creation of illusion images. My main concern is to mislead or trick the viewer. A good example of that is my painting, “The Hidden Tiger”, which was done when camouflage art was so popular. Viewers were accustomed to searching for an animal or something that is hidden within the scene. They could not find the hidden tiger. I had tricked them by hiding the lettering, “THE HIDDEN TIGER”, which was the stripes on the tiger. Sometimes, it is necessary to turn the image upside down to see the solution. 

The Hidden Tiger

Q. Sounds like it requires lots of preparation and inventiveness. How much effort and time does it take to create such optical illusions, starting from the concept up until the finished product?

A. Some paintings can be done in a short length of time, while others take longer.  Often, more time is spent on planning than painting. I’m usually regarded as a rather fast painter, but I spend several hours on research and planning. I try to incorporate the elements of good art… things like ideas, drawing accuracy, composition, tonal planning. color, etc.

Q. Finally, what are your hobbies and what do you like to do in your free time?

A. My free time is roaming the jungles of Florida and getting good photos of scenic and wildlife subject matter. Those photos are often used as a reference for my paintings.

Q. Sounds like a terrific pastime! Thank you for the interview Rusty. Wee don’t want to take any more of your jungle exploration time.

A. Thank you, Puzzle Prime.


FLEB is a passionate puzzler and a popular YouTuber. To his YouTube audience, he regularly presents various interesting puzzles he has collected over the years. FLEB is a former TOP10 finisher in the US Puzzle Championships and also a regular participant in the MIT Mystery Hunt. Recently, he released his first puzzle video game – RYB. You can see FLEB’s favorite puzzles on his official YouTube channel.


Q. Hi FLEB! Is this your real name? If not, where does it come from and what does it mean?

A. Hi, my real name is Paul Hlebowitsh. At MIT, people oftentimes call each other by their Kereberos (computer system) usernames. Mine was “phleb”, which when pronounced sound like FLEB! That’s where that comes from.

Q. When and how did you get into puzzles?

A. When I was young, I would often check out books on brainteasers and puzzles. I was a big fan of the “Encyclopedia Brown” books and there was a series of “Clue” books that were similar. When I was in high school, I was lucky enough to know some people who were involved with the MIT Mystery Hunt and I was able to solve it remotely through the internet with their team!

Q. Talking about the MIT Mystery Hunts, what is the name of your team? How did you choose your teammates?

A. The small puzzle team I hunt with is mostly friends of mine from college, who also got into puzzles. We use a bunch of different names, but the most recent one was “The Sweatiest Tryhards”.

The big Mystery Hunt team that I’m a part of is called “Death and Mayhem”, which started way before I joined it. It’s the merger of two teams “Death From Above” and “Dr. Teeth and the Electric Mayhem”. I joined “Death From Above” around 2008, but it was around for a long time before that. I’m not sure where the name comes from!

FLEB’s favorite puzzles

Q. How many puzzles do you have in your collection?

A. Oh gosh, I’m not sure. Probably close to a thousand, but I haven’t counted. I know I own around a hundred Hanayama puzzles alone!

Q. That’s a lot, we definitely need to catch up here! Do you remember the first puzzle you ever got?

A. My first puzzle was a Rubik’s cube, which my parents bought me for my birthday when I was young. It’s a good one to start with!

Q. Which is your favorite mechanical puzzle?

A. For my wedding, a bunch of my puzzle designer friends built me a custom 4’x2’x2′ puzzlebox, which is simultaneously the biggest puzzle I’ve ever had to solve, along with the most complicated. It includes a working telephone which plays messages after you’ve solved individual puzzles!

Q. Sounds very inventive. And what about your favorite brain teaser, or game?

A. For brainteasers, I think I’m going to cheat this question a little bit and choose a collection. I think “What is the Name of this Book?” has the best brainteasers out of any book I’ve seen. They’re all in the “liars and truth-tellers” types of brainteaser, but he slowly guides you to answering ones about people who answer randomly and in a language you don’t understand.

When it comes down to games, I really like “The Talos Principle”. I think that’s the best puzzle game I’ve ever played. Then I think it’d be “The Witness”, “Linelight”, “The Room”, and “Hexcells” in some order.

Q. You are a TOP 10 finisher in the US Puzzle Championship, which is a great achievement. What does your preparation for puzzle championships look like? Do you have any tips for others who are getting into competitive puzzle solving?

A. Mostly it involves creating and solving puzzles. If you want to get into competitive logic puzzle solving, one of the most important aspects is learning how to create logic puzzles! Creating puzzle is a great way to understand new logic puzzle types.

Q. How did you decide to start making youtube videos? Did you expect to make your channel so popular?

A. I wanted to share my joy of puzzles with others! I didn’t expect it would be so popular at all!

Q. What are your future plans for it?

A. I’d love to cover more aspects of puzzles in the future, such as puzzle history and design, but I’d also like to cover some brainteasers and more puzzlehunt puzzles.

Q. We are looking forward to this. What other hobbies do you have, apart from solving puzzles and playing board games?

A. I really like Rocket League! I’m terrible at it, but it’s fun. In the fall, I also love college football. Almost every Saturday during the fall I watch a game or two!

Q. As a last question, what would you recommend to our readers, which want to improve their overall analytic and problem solving skills?

A. Puzzles are a great way to get entertainment!

Q. We completely agree with that. Thank you for the interview, FLEB.

A. Happy puzzling Puzzle Prime!

Leonid Mochalov

Leonid Mochalov is a Russian puzzle writer and inventor, who has published several brain teaser books and patented numerous mechanical puzzle toys. We decided to invite him for an interview at Puzzle Prime and learn about his passions, habits, and views on Pokemon GO. You can see all of Leonid’s puzzles on his personal website.


Q. Hello Leonid. When did you discover your passion about puzzles? Was it influenced somehow by your education or occupation at that time?

A. It happened during my school years. I published my first puzzle when I was 13 years old. Education and occupation had nothing to do with it.

Q. What drives you to make all these puzzles?

A. Ambitions. When I was young I decided to become a famous puzzle creator, such as the great Henry Dudeney or Sam Loyd.

Q. You have invented many mechanical puzzles. Do you ask professionals to build them based on your concepts, or you do it yourself?

A. I post the blueprints of my puzzles and their descriptions on my website for free. After that, various puzzle collectors and companies make physical copies of them.

Leonid’s puzzle blueprints

Q. Designing 3-dimensional puzzles seems incredibly challenging. Can you describe how the process of creating one goes?

A. I have a very well developed 3D imagination. First, I think of a geometric object of an unusual shape, and divide it into smaller pieces. Then the pieces are glued together and the brute-force method comes. Another possible approach is to come up with a single piece which locks the entire structure.

Q. Which is your favorite physical puzzle of all time?

A. My favorite puzzle is the “Chess Cube”.

Q. And which is your favorite puzzle you have invented?

A. The “Pyramid” – it is an analogue of the “Soma Cube”.

By the way, despite the abundance of mechanical puzzles in stores, the real (classical) ones are not more than 100. These two can be classified as such.

Q. Do you like more mechanical puzzles or pen and paper problems?

A. I lost my interest in pen and paper problems in the early 90s, and then I focused my interest on mechanical puzzles. I believe a good mechanical puzzle is worth a lot more than any pen and paper problem. 

      Place the numbers from 1 to 9 in the squared so that all the equations are accurate.

Q. Where can people buy your puzzles from?

A. Many of my mechanical puzzles are sold in specialized web-stores. 

Q. It looks like the new generations do not appreciate problem-solving as much. Do you think there is still appreciation for puzzles nowadays?

A. Not that much in our country. The pick of the interest was in the last quarter of 20th century. After that computerization and shooting games came into play. The contemporary epidemic is “Tank Wars” and “Pokemon Go”.

Q. Do you keep in touch with other inventors, maybe collaborate on projects together?

A. Not quite, I tend to work mostly alone.

Q. Some people find listening to music during work quite helpful. What about you – do you listen to anything while designing your puzzles?

A. I don’t listen to music when I work, because I find it distracting. However, I listen to disco style songs of 60-70s in my spare time.

Q. You seem a bit old-school. Do you work often on computer, play video games, watch movies? What are your hobbies overall?

A. I do non-professional photo and video shooting, so sometimes it is necessary to work with materials on my computer. Other activities I practice are following news, downloading movies and programs, watching Sci-Fi’s and thrillers. I don’t play video games however. I also used to play card games like “Preference” before retirement.

Leonid fishing

Q. You look in good shape; we know you enjoy fishing. Do you do any other sports?

A. I don’t actually. I used to jog, but then gave it up.

Q. Do you think puzzle solving is beneficial for people, especially younger children and teenagers?

A. It is very necessary for development of young generations. Puzzle solving is educational and distracts from drugs and alcohol.

Q. Tell us a funny science joke or an anecdote.

A. Something I find amusing is related to Einstein’s had 2 cats. It is common in the West people to have an opening in the door for their pets. However, Einstein had two openings – one for the big cat and the other for the small cat. It wouldn’t be like that in case of a normal person since the small cat can go through the big hole too.

Q. Thank you for the interview Leonid, wish you all the best in your endeavors.

A. Thank you for inviting me too.