Sometimes a transparent object can be useful in the design process. With blender this is very easy but requires the activation of transparency in two different menu options.
In the material Tab, activate the Transparency and afterward select an alpha value less than 1.
In the Object Tab, click the Transparent object in the “Display” area.
And that’s it. The alpha value is between 0 (0%) and 1 (100%).
Alex Hbaiu's 3D Printer Blog 