Internal Size
The internal size you enter will relate to the opening in the middle of the mount. You should enter the exact size of the image you are framing. By default, we automatically make a small adjustment to ensure your image doesn't fall through the middle of the mount. As an example, if you enter 500 X 400mm as your sizes, the actual opening of the mount supplied would be 494 X 394mm to ensure a slight overlap of your image.
However, our website also has the option to have the aperture cut to the exact size entered - just check the 'Aperture Exact Size' box. This is a useful option if the item you are framing doesn't need to be overlapped or you have already take the overlap into consideration.
External Size
The external size will relate to the exact external size of the mount. You need to consider how the mount is going to be used to decide on the correct external size you require. If you are fitting the mount into an existing frame, the external size would need to match the glazing/backing board size of the existing frame. If you are ordering a new frame as a separate item on our website(or virtually any other picture framing website in the world) you would need to order the same frame size as the external mount size.
Title Box - Optional
Select this option to have an additional aperture cut in the mount that can be used to put a printed description of the main artwork, typically called a title box. The title box will be 100mm wide and between 10 - 20mm in height. The minimum bottom width border required to include a 10mm high title box is 40mm. To achieve a larger height title box aperture, you will need to increase the bottom border width. Depending on the text size used, it is suitable for 1-2 lines of text. If you decrease the width of the bottom border to below 40mm, the title box will be removed and the option will not be available to select.
Our full measuring guide can be found here.