A few comments on wood and watch inserts before we start:
-- It must be wood.
-- Corian and other synthetic materials look like what they are, plastic, and nobody likes them.
-- The more bold or outrageous the grain pattern, the better.
-- The only solid colors that are popular are black (Ebony) and white (Holly).
-- Everybody loves "Birdseye Maple"
-- Wood with tight grain patterns and small features will look better.
-- There is no restriction on species or hardness because we will be using CA glue to "harden" the softer wood.
-- The wood MUST BE DRY. Any residual moisture will result in shrinking, and the inserts will fall out and the smooth surface of the watch will disappear. If there is any doubt about the moisture content, allow the bare wood to reach room temperature (70F), and then hold it against your cheek. If it feels "neutral" the moisture is at equilibrium. If it feels cool, it is too moist to use. Try it. It works!!
I cut and store all wood in blanks that are 2-1/2" square by 3/4" to 1" thick. The blanks for a women's pendant watch can be smaller, but I prefer not to make that decision when I am cutting wood or have to keep them in a separate inventory. I rarely coat the wood with a sealer, preferring to let the wood make the decision if it wants to be made into a watch.
All watch inserts of a given style are alike, regardless of who is selling them. Buy them where they are at the lowest price. Some inserts are made by Seiko, some from unknown sources, but all are made in China. Some will have a Stainless Steel back while others are plastic. Some will have a glass crystal, and some will be plastic. Some are available in chrome and other plating, but most of them are "Gold". Some of the "Gold" is not very durable, while others will last longer. Regardless of these differences, they are all the same price, and it is up to us to find the better ones.
The inserts are available from many sources, but Klockit has a good selection, and they have always given me the better price on larger quantities.