Well, I haven’t yet been asked most of these questions, but I know I’m going to get some, so here:

How do I build papercraft?
I have a whole page dedicated to this, a series of videos on YouTube, and a panel I hold at cons on that subject.

How do I open PDO files?
PDO files can be opened with Pepakura Viewer 4.  It’s a free download.  As of the most recent release, it is now bundled with Pepakura Designer.  The software is Windows only, but if you’re a mac user, you might be able to run it through Wineskin.

Why isn’t there a PDF file?
Because the PDO contains both the pattern and the instructions at a much lower file size.  And with the newest version of Pepakura Viewer, you can easily print the PDOs to a PDF yourself using “Print to PDF”.  If you really need one, though, maybe I can provide one.

Can I have an A4-size pattern?
I live in the US, where letter is the standard paper size.  If you’re country uses A4, that should not be a problem – the letter-size pattern will still print, and will be no less buildable.  At worst, the size may be very slightly reduced, but this depends on your paper/printer configuration.

Can I have an unlocked PDO?
No.  I lock my PDOs for security reasons, and this is not something I give out lightly.  If you really want it, you’ll have to prove to me that you have a legitimate need for the unlocked pattern that the locked version will not suffice for, and that you’re trustworthy (which is nigh impossible considering how paranoid I can be).

But I can remove the lock myself…
If a designer wanted you to have access to the unlocked PDO, they would have provided it.  Do not remove the locks from locked PDOs under any circumstances, unless you have the designer’s permission.  At best, you are disrespecting me and my works.  At worst, you are outright stealing them.  The Mexican hacker incident was a result of people doing just that, and caused me not to share any patterns at all for several months.  If you are trying to rescale the model, there is a right way to do this – print it to a PDF, and change the print scale.  And don’t worry if the paper size doesn’t match – like I said above, this is rarely an issue.

Can you resize or recolor one of your models for me?
I can, but this would be a commission (usually tier 1).  You can do this yourself, though, if you like.  If you use Pepakura Viewer’s print to PDF feature, you can create a PDF copy of the pattern, and most PDF viewers have print options that will allow you to scale it when you print it.  Recolors can be done by editing one of the included texture files.

Can I sell a model I built based on your pattern?
No.  My patterns are for personal use only.

Can you send me (Model X) from your gallery?
Probably not.  Many of the models in my DeviantArt/Facebook galleries were not designed by me.  Those models are the property of their respective designers and it is not my place to share them.  The models that were designed by me will likely be released here eventually, but direct sharing those has caused me some significant problems and a close call involving some Mexican hackers.  I will only share my future release models with members, close personal friends and established papercrafters who have proven themselves trustworthy.

Why isn’t (Model X) on your site?  According to DeviantArt/Facebook, you designed it.
I’m still in the process of releasing a lot of my older models.  Some are scheduled, but not up yet.  Others require additional edits or testbuilds before they’re ready for posting.  And there are others that I’m keeping exclusive for now, to use as contest prizes and gifts, or were commissioned models whose exclusivity period hasn’t ended yet.

I’d like to see you build a (Character X).
If I have a pattern available, or you can provide one, maybe, but no promises.  If not, and I’d have to design one myself, no.  Designing patterns takes a lot of work, and I cannot do that simply on request.  I may, however, if I feel the pattern is within my ability to design, be willing to design a pattern on commission.