You should upload your file to Shapeways in order to get an accurate quote in all eligible materials, to check models’ printability, and to eventually order or even sell your designs! You'll need to signup for an account if you want to upload your own files.
To do this, log in to your account, hover over the Start making button on the top right and click on UPLOAD NOW. You can also head straight to the upload page.
Locate the the grey "Choose a 3D file or drag it here" area and choose your units (don’t worry, your model can be re-scaled later).
You can click this area, this way a dialogue will pop up. Select your file you want to upload, this file be start uploading right away.
You can also drag and drop your file into this area.
A model page will load and you will be able to proceed from then on.
You can upload the following file-types:
DAE, OBJ, STL, X3D, X3DB, X3DV, WRL, 3MF, STP, STEP
For textured files (to print in full color materials), upload a ZIP folder containing the 3D file and the texture file in one of the acceptable formats:
3D files: OBJ, MTL, DAE, WRL, X3D, X3DB, X3DV
Texture files: GIF, JPG, PNG
Make sure the ZIP folder contains these files only, and that they’re not in an extra folder within the ZIP folder.
We can only accept files that are smaller than 64 MB and contain less than 1 million polygons. If your file exceeds this limit, consider either compressing the file to a ZIP folder, and/or reducing the polygon count of your model.
You can find the corresponding tutorial HERE.