The images to the left are of an example of a 3-D acrylic front, which is placed inside the frame and replaces the glass.
As this protrudes forward from the frame, it allows the frame to sit against the wall. These fronts have rounded corners to the sides with no joins and are only joined at the top and bottom edges, this allows the object (poppy in this instance) to be seen from above, below and from either side. They are a lot more light and airy giving a much more contemporary feel in comparison to traditional deep frames where the object can only be sen clearly from the front, as is the case with the boxes behind the frame in the examples above.
We can have these made to any depth or size in 3mm or 5mm thick acrylic to suit the task.
These fronts not only offer protection from dust and tampering, but offer 90% UV protection too.
See here for more examples of Acrylic 3-D Frames.