This is a simple model of a dog tag with a convenient capsule that can store contact information of the owner. The trick here is to use a transparent filament for the first and last layer (excluding the name) of the tag while decreasing the number of solid layers to a minimum. 

After some trial and error, I found out that setting the solid layers (top and bottom) to 1 and setting the minimum shell thickness to 0.2 worked out the best. The dog tag is fairly transparent and the infill is visible. 

The results may vary depending on the transparent filament used. I used the hexagonal infill set on 15% and I personally like the look of it, but any combination can be used.

You can import the config attached to this, and then you will need to start printing with transparent filament, then do a colour change after the bottom solid layer, then another colour change for the top solid layer, again swap to transparent filament and lastly do a colour change for the dog's name layers.

Printed with PLA and ironing enabled, for a smooth finish.