Hi there!

In this Instructables, I'm going to go over how to build a 1:1 scale T-Rex skull out of cardboard, paper and glue (essentially paper-mache). Don't let the namesake fool you though, movie studios, artisans and prop makers have been using it for centuries and, as you can see, the results can be pretty amazing if you persevere..

Step 1: Plan Your Project

The very first thing I did was I made a plan. For this, I modeled the skull in 3D using Blender (completely free). This sounds daunting but first hit up blender.org to get the program and then I suggest going through the tutorials on gryllus.net .

I recommend using lots and lots and lots and LOTS of reference photos. I googled T-Rex skulls till Google insta-filled my search bar with T-Rex every time I fired up a search engine. I think I accumulated over 90 images of T-Rex skulls and even contacted the Smithsonian for some reference shots of the back of the skull. Seems nobody ever photographs the BACK of a skull. Strange.

From there, it is a simple matter of unfolding the model. You can do this in Blender using the UV Editor OR you can get a program like Pepakura Designer. The program will let you unfold your model and makes a printable version without a great deal of effort. If you need more tutorials on that one, Instructables has a number to choose from.

Step 2: "It's Only a Model" "Ssssh!"

Surprise! More Planning!

Next, I made sure this was going to work so I made a model that was 1:16 scale. This is thin paper, but it really helps to just get an idea that what you are going to make works in the large scale. I discovered there were some errors on the back of the skull that I'm very glad I fixed in the small scale first.

It also helps you learn where your pieces mesh together and where you might have trouble. Trust me, if you have trouble meshing 2 pieces that are 2 inches apart, it gets much much MUCH harder when those pieces are 2 feet apart.

Step 3: Print, Prep and Trace

Ok, so the measurements for Mabel (friend dubbed her that) are 5 feet from neck nape to jaw tip and roughly 2 and a half wide at the back jaw. That is a lot of paper so I had the pieces printed up at a printer, assembled them into the pieces and then began tracing them onto cardboard.

I was lucky enough to have Tandy Leather Factory in Tampa donate several large used cardboard boxes that they ship their leather in. I recommend a nice, thick cardboard and tracing with a Sharpie.

It helps to tape down your patterns when doing things large scale. A good balance of masking tape is needed, you want something that will hold but something that won't rip your pattern. Experiment, test a few first. I found a few rolls at a dollar store held nicely without making adjustments impossible.

Also, use a thin ratcheting blade and have several on hand. You're going to go through these like popcorn doing this. No lie, I went through 4 full sets of blades just cutting the cardboard out. Be careful here, don't rush. One slip is the difference between an afternoon working and an afternoon in the ER.

Step 4: Cardboard- ASSEMBLE!

Ok, now we begin assembly. There were well over 40 pieces for the pattern I made but I made them from scratch so I was familiar with the fit. This is going to take time. And patience. And more time.

When building something large scale and out of cardboard, warping is a giant factor. If you find something has warped out of simply being able to tug it back into place, rubbing it with a damp paper towel will often give you enough flex to bend it back into place. DON'T soak the cardboard, dampen it slightly.

Edges and seams can be attached with simple PVA glue, give it about 20 minutes to dry (depending on weather) and it should hold.

TIPS FOR THIS SECTION:

Use a thin amount of PVA glue. The more you use, the longer it takes to dry
If 2 pieces won't stick, try sanding the pieces with some 120 grit sand paper. Glue likes a rough surface.
Measure often. Take long walks around the piece to make sure it LOOKS GOOD. Sometimes fudging your plans is needed to make something look interesting.
Try and brace your piece if warping is too much. I ultimately ended up cutting out some 1x2 wood in order to make sure pieces were the right distance apart.
Thin masking take helps hold pieces in place while they dry. Seriously, don't be afraid of going through rolls of tape.

Step 5: And More Assembly....

More and more and more the pieces start to come together. What can I say, this is .... time consuming. I don't want to admit how many hours this took, but suffice it to say that if I had a penny for every minute, I wouldn't be able to move them without a forklift.

Again, make sure you keep things even. As you can see, things are kind of 'flexible' at this stage so keep building and keep checking your angles.

If an area feels too weak or wobbly, don't be afraid to glue on extra pieces of cardboard over the seams. This is paper thin at this stage, shimming things up is not a bad thing.

Step 6: Chewed Paper...

Fun fact, Paper-Mache is french for Chewed Paper. They used to get orphans to chew paper so craftsman could use it to build with.

No Orphans were used in the building of this skull.

Anyway, now you start to cover over the lines and seams. I recommend a thick paper a la grocery bags. Most hardware stores sell a thick paper in giant rolls for about $12 that are 36" x 200 feet or there-abouts. The thicker, the better. A thin wash of 1:1 PVA glue and water helps it adhere and stick down. It helps to work in small patches and, as someone described me doing "fluttering" around the work. If you get any one section too wet, it tends to droop and wilt.

Any areas that need filling out, I recommend crumpling up some of the thick paper, dipping it in the glue bath, and pushing it into place. Then, cover it over with more paper.

Keep building up more and more layers, like an ogre. If something doesn't look right, I recommend a small Japanese wood saw (it cuts on the pull rather than the push) to trim it back down to size.

This is where it goes from 'Ugh cardboard' to 'oh, neat!'

Step 7: "Fleshing" It Out

Now, for the more detailed areas, start using REALLY thin paper. Most hardware stores will sell a roll of 1'x200' paper that is very very thin.

We continue putting on little ripped and cut pieces, adding detail as we go.

At this stage, I like to thicken up my glue mixture. I maybe use a 3:4 ration of water to glue. The paper also absorbs a LOT of glue so you go through it fast. At this stage, I stopped buying bottles of glue and started using jugs. In total, Mabel devoured 2 gallons of PVA glue.

You can crumple pieces of paper up for texture and smooth it out again with more paper. Smaller pieces of paper allow for more detail, but larger ones give smoother lines. This ... statement might not register until you've put in about 50 hours in the material though. Trust me, though, once you get it, it'll be a lightbulb moment.

Step 8: Finishing the Sculpting

Ok, here I switched to using untextured toilet paper and wood glue to finish it up. I used the giant commercial grade rolls of toilet paper and it took very little bit for this part. I used the cheapest toilet paper possible (stuff I could not possibly imagine using) and applied it by putting glue on the surface and then placing the paper in place.

The thinner the material, the better your texture. The color began to muddle at this point as white plus yellow equals a cream hue. I also had to touch up a section of the nose and brow with a bit of epoxy because, well, everyone kept coming up and patting and rubbing there during the build.

I know it doesn't show up well in photos, but for some reason people can't resist petting the dinosaur.

Step 9: Prime!

Always prime your work. Always. I laid down a thick layer of exterior white paint and then sanded it down. This smoothed away any lines from where paper met and also gave it a solid look.

I confess, I was VERY tempted to keep the skull white but took a vote amongst friends and ultimately decided fossil brown was the way to go.

However, prime everything. Prime it with 2 coats, letting them dry well between. Trust me, it protects your work and makes it stronger and allows you to paint all the easier.

Step 10: Paint!

I regret not getting more photos of the painting process but it is a ... well, messy process. My hands are usually any color but flesh tone for a long time.

Don't ever use a single color of paint, either. Even if the pieces is 'one color' there are always high and low light colors. There are 5 shades of brown alone in the paint, along with some red and purple in the shadows. For tips and tricks on painting, see my Steampunk Dodo Case tutorial

And with that, tada! Full sized 1:1 T-Rex Skull!

This same process can be used for any number of builds, too. I'd like to give a shout out to Gourmet Paper Mache as his site has lots of wonderful tutorials and his book is amazing.

I'd also like to thank the Tampa Hackerspace as they put up with a lot of my shenanigans during the build and she took up a lot of space. In fact, if you drop by for a tour sometime you can still see Mabel there!

Step 11: To Be Continued....

I'm working on the teeth...

I switched them mid-build from paper mache to EVA foam because it's softer and people couldn't resist sticking their hands in the giant skull full of sharp sharp teeth.

I'll write up a separate tutorial for sculpting with this stuff another time though! Check back for more!