# Why isn't this object becoming transparent in the render?

I'm new to Blender and trying to make an image. I'm almost there but something is confusing me. Right now, I have this blue rectangle that I want in the same plane as the other objects. For example, here it is from a couple angles:

and rendered:

Now, I want that blue rectangle to be mostly transparent, so you can see the rest of the shape that it coincides with very clearly. So, I went to the materials tab with that object selected, clicked the transparency box, and messed with the alpha parameter, making it very low:

Now, when I render it, it does look different...but isn't actually transparent:

what am I missing here? How can I achieve this?

• Those transparency settings are for viewport only, not materials or rendering. How are you rendering this? – Duarte Farrajota Ramos Feb 22 '18 at 19:40
• @DuarteFarrajotaRamos just hitting F12, which does Blender Render. – MasterZibZob Feb 23 '18 at 3:37

In the material panel, Set transparency mode from Mask to Z Transparency. This will allow objects behind it to show through.