Both provide a popular sleek modern appearance to your artwork and both use crystal clear panels of acrylic however there are some substantial differences between the two.
First, the HD Face Mounted Acrylics use 1/4″ panes of acrylic while the Acrylic Glass Prints use 1/8″ thick panes. This can make the HD Face Mounted Acrylic look a little more substantial up close however it also adds extra considerable weight to the product.
Second, The HD Face HD-mounted acrylic has the image printed on either a luster or metallic photo paper. This allows high-resolution images to best take advantage of a wider color gamut and higher-resolution printing. The paper is then mounted to the acrylic glass from behind. With Acrylic Glass Prints, the image is printed directly on the back of the acrylic and finished off with a layer of white. This makes producing the print easier and less expensive. The disadvantage is the color gamut is more limited so artists and photographers who ar exceptionally particular about color accuracy and color gamut might find the HD Acrylic Prints more capable.
Ultimately the Acrylic Glass Prints are lighter, and easier to produce and ship, therefore the cost is much less.