ordering blender model

How will I know how big my model is I uploaded and selected millimeters if it is from blender. I really have not used blender all that long. Is there an option to pick height when ordering? I know the model is about 9-10 grid squares high.

Hi!

If you press the N key while in Blender you should see the "Transform properties" window.

Select your object (in "object mode") and that window should show the dimesions of the object in Blender units.

If you select millimeters when you upload the file to Shapeways, those Blender units will represent 1 mm/Blender unit.
So a model that is 2 Blender units high will be 2 mm high when printed.

The grid squares are not a good reference, since you have major and minor grid squares and they can represent different measurements based on your settings (check the "View properties" for grid-related settings).
If you zoom in you get 1 gridsquare per unit but if you zoom out enough you will get 1 gridsquare per 10 units and barely see the minor gridlines..

For that reason you should keep an eye on the "Transform properties" window to see the exact dimensions for your object(s) and you can also use that window in "Edit mode" to see the coordinates of vertices/faces/edges or the mean values for the coordinates of all selected vertices/faces/edges.