northern pine ponderosa pine alder poplar maple oak ash cedar cherry walnut obinji and other woods and of course the results vary widely with the color tone and character of each type of wood successful demonstrations have also been done on ply bamboo cotton leather and masonry ply bamboo is a very hard wood product does not stain well with conventional products but is susceptible to coloring according to the invention other substrates are suitable so long as they are made of a material capable of binding the mineral salt in the presence of the oxygen source according to the invention effects may vary with the order of application of solutions a and b in general starting with b and finishing with a yields a similar color but less nuances of wood grain which could be preferable in certain applications in simulating aged wood for example the a solution should be applied first for a non aged appearance and an even color the b solution can be applied first it may be that applying b first makes for a more superficial penetration of the linked color in the wood but this may be appropriate for thin substrates with porous substrates such as fabric or leather it is preferable to soak the substrate in the solutions to ensure even staining the results also vary with the additives included in solutions a or b such as pigments or dyes citric acid bleaches alcohols solvents thickeners tableting agents finishing agents such as an appropriate overcoat of acrylic and other resins.