It is not obvious to most dealers, buyers or even experts in the field, but the simple difference between sawn or sliced veneer material provides absolute proof of the date of the furniture. There are few elements of furniture construction which are as conclusive as this difference in how the veneer was produced.
In 1805 the French invented a mechanical saw (scie a bois montant) which was able to saw the veneer much more evenly than the two men working by hand. Instead of the saw cutting down through the log, the wood was attached to a carriage and moved upward against the saw, rising as it was sawn, thus the name "saw
In America and some other countries large circular saws were redesigned to saw veneers. This produced a very uneven surface, as it was nearly impossible to control the accuracy of the large spinning saw blade. This method was replaced by slicing machines by 1850 in most cities.
It is impossible for any piece of furniture made before the Industrial Revolution to have an original surface made with sliced veneers. However, it is entirely possible for furniture made after the Industrial Revolution to have an original surface made with sawn veneers, such as high end recreations. I always use sawn veneers in making my furniture, as they are natural and stable, and represent the original material which I value highly for authenticity.