Instruction Brochure included in boxes of Bainbridge BevelAccents (now discontinued). Can be used to install edge-bevelled strips of matboard or covered foamcore within the sight opening of a cut mat to create the appearance of a cut deep bevel.
When using this technique, first make a small mock-up of whatever bevel depth(s) you intend to install. (If more than one layer, ATG them together as needed with the bevels aligned.) Measure the width from the sight inner edge to the top edge of what you are installing. Increase the opening size of your top mat by double this measurement in both directions. That way, when you install the strips you will end up with the intended sight size of your mat.
When using this technique, first make a small mock-up of whatever bevel depth(s) you intend to install. (If more than one layer, ATG them together as needed with the bevels aligned.) Measure the width from the sight inner edge to the top edge of what you are installing. Increase the opening size of your top mat by double this measurement in both directions. That way, when you install the strips you will end up with the intended sight size of your mat.