2．We see the world in three dimensions．Now，we can print in three dimensionst，too，thanks to a manufacturing process：3D priming．
3D printing or additive manufacturing is a process of making three dimensional solid objects from a digital file．
The creation of a 3D printed object is achieved using additive piocesses．In an additive process an object is created by laying down successive （連續(xù)的 ） layers of material until the object is created．Each of these layers can be seen as a thinly sliced horizon till （水平的）cross-section of the eventual object．Today's 3D printers are being used to print everything from design models to jewelry，crafts，product parts，body parts，and even food．
3D printing starts with making a virtual design of the object you want to create．This virtual design is for instance a CAD （Computer Aided Design） file．This CAD file is created using a 3D modeling application or with a 3D scanner （to copy an existing object）．A 3D scanner can make a 3D digital copy of m object．
You will have to prepare a 3D model before it is ready to be 3D printed．This is what they call slicing．Slicing is dividing a 3D model into hundreds or thousands of horizontal layers and needs to be done with software．
Sometimes a 3D model can be sliced from within a 3D modeling software application．It is also possible that you are forced to use a certain slicing tool for a certain 3D printer，
When the 3D model is sliced，you are ready to feed it to your 3D printer．This can be done via USB．SD or WiFi．It really depends on what brand and type 3D printer you have．
When a file is uploaded in a 3D printer．the object is ready to be 3D printed layer by layer．I'he 3D printer reads every slice（2D image） and creates a three dimensional object．
Before you pick up a 3D printer and experimenting in the 3D world，consider how big the objects you might want to create，If your goal is to print foot-long rulers，you'll fall short of that goal if the printer you choose can only handle objects smaller 6inches in height and width．
Another reality check is print speed．，You'll be able to knock out a days worth of chores（瑣事）while the primer is running，with a typical 4-inch model requiring as many as 12 hours to print．As with ordinary printers，print speed also depends on how well it prints．
Title：A liegiliners'Gmk to 3D Printing．
| What is 3D printing？ | 3D printing is a process of making three-dimens ion objects out of a digital file．
An object created with 3D printing （71）consistsof a number of layers of material． |
| How does 3D printing （72）work？ | The first （73）stepis to make a virtual design of your （74）desire\wanted\targetobject．
A（75）prepared3D model is slictxl into a hujzc number of layers with software or some （76）toolfor a certain 3D printer．
The sliced model is （77）fedto a 3D printer
The 3D printer （78）forme\makesthe layers into an entire object step by step． |
| What else do you need to know？ | The （79）sizeof what you intend to make is a factor in your choice of a 3D printer，
Prim speed is associated with print （80）quality． |
