For cubes larger than a 5x5 there are two options: pillow it or to make the outer layers bigger.
You can clearly see that the 17x17 has larger outer layers.
Tony fisher has made a cubic 7x7 here
The 6x6 also has slightly larger outer edges
What is the brand of the siamese cubes given out at nationals? Ask for pictures if you need them.
I purchased a Rubik's cube, or a 3x3 variant, at at an antique store ( I know that doesn't make it old) and I want to know if there is some way I can tell how old it is. It seems to be some what old, and it has an old "how to" book with it, neither were in any packaging though. The book is called "You can do the cube" by Patrick Bossert, it was published in 1981. I tried a quick google search and couldn't find a mention of the book having been packaged with the cube however. Further information about the cube is that it does not have a Rubik's logo (or any other for that matter) and it has a western color scheme. The stickers are duller than my three- four year old official Rubik's cube. The cube turns stiffly, to be expected of course if it has any age and has never been lubed. The stickers are in very good condition, showing very little wear only in the form of being slightly dirty, with exception of the center orange sticker lifting somewhat. I have not looked into the core so if there is something I can learn by doing so please let me know. So that's all I can tell you guys, it'd be great if y'all could help me out.
It's as cheap as a shengshou but it doesn't have any real look of it in the pictures..