All stained products should use a stain controller prior to staining. Some species stain better than others. Please see the full color Reeb Interior Door Catalogs for stainmeter.
Good preparation is critical for good results. Sand the door and keep it very clean. Use a tack cloth to remove all particulate matter. Stain condition following manufacturers' instructions.
Stain product and let dry. Finish with two or more coats of finish. Interior clear finishes can be varnish, tung/teak oils, laquers, etc.
Oil and Water Based Varnishes - Oil finishes dry slower and give the coat a slight glow in color. Water based varnishes are fast drying and have little or no color and depth.
Oils like tung and teak oils are wipe on finishes. They dry slow and require many coats (4 or more). They typically give an amber color to the finish.
Lacquers are fast drying finishes that are durable and give nice depth and soft color.
A note about Pine:
Pine sometimes varies dramatically in density. The best stained pine finishes come from Ponderosa Pine. This species has the best consistency in density and finished nicely. This is the "best" pine door species. All exterior pine doors are domestic Ponderosa Pine.
The "White Pine" product is beautiful in unfinished color consistency but has characteristic of very pronounced color variation when stained. This variation is not a defect of the wood but is because the variation in cell structure and absorption rates of stains. This is Reeb's "better" product. This product is great for clear coats and paints.
Plantation Pine has very pronounced grain patterns. The trees it is made from are very fast growing and the growth rings are very large. It can stain inconsitently. This is a "good" pine door that is made very well and good for value stain/paint needs.