Building the sponge has been a fun hobby but after not touching it for almost a year, losing interest, and not having much time to work on it, it's time to call it quits. It's been disassembled and "filed" away. I was surprised that I felt a little sad taking it down. It was a labor of love when I started.

Now what?

Mengermania will continue to live on for others who want to build their own sponges. The instructions are still useful and I'm happy to continue sharing the photos. Over the next few weeks, I'm going to rearrange a few things to put more of a focus on the instructions, photos, and general information about Menger sponges. The blog will still be here but not used much.

I've renewed the mengermania.com domain for another year but will not be renewing it next year. However, the site will still exist as a microsite hosted off of my main site, C82 at mengermania.c82.net. I can't just get rid of the site completely!

So for the few of you still following, thanks for reading and keep folding.

Photo courtesy of Lenore M. Edman, www.evilmadscientist.com.

Lenore Edman was adventurous enough to create her own unqiue fractal food—Sierpinksi cookies and they look great. They would be a yummy treat on a chilly April evening like tonight. I love that someone was geeky enough to take the time and make them. Plus, they're relatively simple to make. The author went so far as to create a cookie from a level three carpet…I wonder who will create a level four or even five? That would be one big snack!

Animated level nine sponge

I stumbled across Peter Miller's animated sponge a few days ago and was amazed at the simple beauty of a cube growing into a mind-blowing level nine sponge. His animation is 14-minutes long and is possibly the only animation out there of a sponge of that complexity. His page on sponges has a few other goodies including how to optimize sponges for 3D graphics.

Metal sponge

Bathsheba Grossman, an exceedingly talented sculptor, made a metal level four sponge. It's small enough to fit in two hands and would look great anywhere. I would get one immediately but unfortunately, they're no longer for sale due to production difficulties. Cutting all those holes must be pretty difficult so it's understandable. Bathsheba creates many other amazing works of art—many available for sale.

3D level four sponge

Jeff, a Mengermania reader, sent me his rendering of a level four sponge comprising 336,384 polygons. It took its toll on his computer during the rendering process but it came out great. He's working on building his own level three sponge and I wish him the best of luck.

Post-it sponge

Since May, when I wrote the post about making sponges out of Post-its, I've been slowly creating a level two sponge out of Post-its at work. I was only able to create a few cubes a day during my limited free time but it turned out great. It's just over six inches square and was made from 864 Post-its. Two photos of it are in the gallery.

I'm always on the lookout for more Menger sponge art, so if you've created something, let me know in the comments below or send me a note.

First, let's go over the basics. Preparation is the act of creating units—the individual pieces that compose cubes and the final sponge. Assembly is the act of interlocking units to create cubes and attaching them to the sponge.

Basically, units create cubes and cubes create sponges: units » cubes » sponges.

The easiest part of assembly is the first cube, requiring 6–10 units and a few easy steps. Attaching additional cubes can be done three ways:

Pre-assembly

The first method involves building a cube separately and leaving flaps exposed on sides that will interlock with other flaps. Pre-assembling cubes works best for cubes that will interlock with only one set of flaps, such as cubes on the 12 edges of a level 1 sponge.

Note: all cubes end up interlocking with at least two sets of flaps in all sponges, but flaps are exposed during assembly until more cubes are attached so some cubes will interlock with only one other until more are attached to them. For an example, see the first level four photo with some cubes attached on a single side.

Assembly on the fly

The second and most used method is used for cubes that interlock with two or more sets of flaps. Units should be added to the sponge one at a time.

Trying to attach a pre-assembled cube to multiple sets of flaps is enough to drive anyone mad because it is nearly impossible to make the flaps behave properly. (Don't believe me? Try it…now try it with three sets of flaps.) Assembling on the fly makes life much easier. Most of the time on larger sponges is spent assembling on the fly.

Some pre-assembly required

The last method was learned the hard way after many frustrating attempts and mangled units. There are areas in all sponges that are difficult to panel, such as the insides of the smallest holes. You could try to assemble the cubes in these areas on the fly and panel the necessary sides afterward, but depending on the direction of the flaps, you may find yourself wishing there was an easier way. The trick is to pre-assemble a cube up to step four in the cube assembly instructions and use that to start assembling on the fly. Explaining this without a demonstration is a little difficult and without access to a video camera.

While this can be a tricky method to master, it makes panelling those hard-to-reach sides easier since the bottom of the set of units after step four is the hard-to-reach side. Essentially, it's pre-panelled.

Mastering these assembly methods takes time and practice. By the time you finish folding a couple level one sponges, you should be able to do most of them quite well.

The feeds have also been fixed. I apologize for the problems anyone has been experiencing. You won't need to change your subscriptions as the fixes are already in place.

One additional fold is necessary to make Post-it units strong and it's very simple. Regular Post-its are three inches square and pretty thin, so they need to be torn and folded one extra time to give them the strength necessary to create a decent sponge. (One Post-it creates four units.) The sticky backing of some units will also need to be hidden inside folds so it doesn't interfere with assembly. It won't be used to hold any part of the sponge together because remember, the onlly tools needed to build Menger sponges are your hands!

Instructions for making units

1. Fold a post it in half twice—Make the creases sharp with a finternail to score them for easy tearing.
2. Turn over and fold along creases again—Score each with a fingernail again.
3. Tear along creases—If the Post-it doesn't tear easily, fold and score creases again or tear along a straight edge.
4. Fold each unit in half—Remember to hide the sticky backing for some units by folding the sticky part on itself.
5. Lay two units on top of one another to create a cross and fold flaps.
6. Turn over, and fold top flaps—Post-its will have larger flaps than index cards making the sponge sturdier.
7. Separate units—Repeat for additional units.

See the instructions for cube assembly.

Folding each unit in half before creating the flaps adds the necessary extra strength and for those with the sticky backing, "seals" the unit nicely making them a little easier to assemble.

The units from Post-its are great for making smaller level one or two sponges. They may work for a level three sponge but they might not be strong enough. Feel free to give it a shot though. To add a little color to a sponge, try using some multicolored Post-its too. So the next time you spot some extra Post-its lying around your desk, try making a sponge or two.

Back in 2003 when I completed my first level three sponge, I started to create this sponge but stopped due to demanding schedules and various other things. I kept it assembled until January of this year when I dug it out and disassembled it…only to begin reassembling it. Why? Units became disreputable and it broke in half due to it being shuffled around over the years. I thought it best to start over but I saved the units to reuse them.

All old units have now been reassembled which means I have to create new units as I go. I usually do one pack of notecards (1,600 units) at a time, then assemble them. Creating units takes a little while since each notecard needs to be torn in to 16 equal pieces that isn't nearly as fun as assembling them but it's necessary. I definitely won't be stopping though. The assembly will just slow down a bit.

• Puzzle Hunt—An intriguing animation about a little girl trying to track down a turtle in a forest while a level 4 sponge assembles itself around her. It may sound confusing but it's very well done and quite enjoyable.
• Silk—A Taiwanese thriller/horror movie about scientists using a Menger sponge to harness and study ghosts and the afterlife. It seems to be a bit of a stretch but the trailer makes it look pretty interesting. I haven't seen it yet, but wouldn't mind getting my hands on it. The Menger sponge animations are very cool.
• Business Card Menger Sponge Exhibit—As possibly the most well known sponge project, Jeannine Mosely completed a level 3 sponge in 2006 from ordinary business cards and had an exhibit for it at the Institute for Figuring. Her Web site for the project it was my original inspiration in 2002 to begin creating my first level 3 sponge.

There are more, but these three are the first and most elaborate few that I've found so far.

Most of the content is still the same but the overall design and home page have significantly changed. The old Status section has been renamed Progress and is now in its own tab, rather than on the home page. This was done to make room for highlighting other areas of the site such as recent photos and blog posts. The logo has also been touched up a bit.

I hope everyone enjoys the new look. It should not be changing any time soon!