New software called Mineways enables you to export your Minecraft creations into models and texture maps ready to send to a 3D printer. To do this, you'll need an exported world map from Minecraft with your favorite design inside. Using a birds-eye view, you can then select the area you want to print, save it as a model, and then send it over to a 3D printing service like Shapeways. It's not fool-proof, and your models might need some tweaking to work, but the software is pretty good at removing objects that are floating in space or impossible to construct. It will also hollow out the interior of your designs, preventing overuse of the raw material and lowering the cost. Other tools like Minecraft.print() have performed a similar task before now, but Mineways is the first to export with full color.
Developer Eric Haines illustrates the software using a full-color model of the Eiffel tower based on his own design, which is printed from sandstone at just under 5 inches tall, and costs a little over $25 to print. Mineways is free and open-source, and has been extensively documented — even down to instructions for best results from Shapeways. He says that results on a huge scale are possible (though this build is created using an alternative system), but don't expect ambition to come cheap.