| Making a Tone³ is not
very difficult. The basic material is several gray cards. Cut out four squares,
about five inches along each side, from two gray cards. The gray card can
be cut to almost any size, but I've found that a cube much less than five
inches across is too small for many uses. You want to be able to photograph
it at a large enough image size without being so close as to have the lens
extension factor affect your calculations.
Whatever size you decide upon, you'll also need to cut two more same-sized squares from cardboard or mat board. You'll need to attach a dark material to the mat board. I found a suitable black flocking material in a display supply store. The flocking material comes in rolls and is used in store window displays. Black felt or velvet might also work. It's important to choose a black material with a texture so it will show up as shadow detail. I attach this to the mat board pieces using a spray adhesive. Don't do this in your darkroom or print finishing area, because spray adhesives can damage photographic materials and should only be used in well-ventilated conditions.
After all the squares are ready, assemble the similar-toned pieces together by taping them along one edge (i.e., tape the gray sides together, as well as the white sides and black sides). Refer here to see how this is done. Next attach two of the pairs together by taping along the three common edges when you roughly form a cube. The difficult part is attaching the third pair that completes the cube. Taping these can be tricky and the result usually isn't flawless, but the resulting cube is almost always serviceable.
Since constructing the Tone³ can be frustrating and time consuming, I've had a manufacturer make them for me. E-mail me for information on how you can purchase a Tone³ or fill out this form and I'll contact you with info.