The Big Question—What is 3D Printing? - 3D Printing: Build your Own 3D Printer and Print your own 3D Objects - page 2

Figure 1.1 A conventional printer, in all its glory.
Printers print on a flat surface. Another way of looking at this is that they print in
only two dimensions. Think back to your early math classes and you may remem-
ber discussions of dimensions. A one-dimensional object is nothing more than a
point in space that can move along a fixed line (like the period that ends this sen-
tence, but without any volume). A point has no height, width, or length. It's simply
a point. Likewise, a two-dimensional object is flat; it has length and width but no
height. Figure 1.2 shows some examples of one-dimensional and two-dimensional
objects.