This sample shows an iron stain (this is why you shouldn't use iron nails in your finished frame) and tannin staining. Tannin stains develop when the timber becomes wet and the natural tannins wash onto the surface. Uncleaned frames may also have footprints and other marks on them.
This is the most common finish and brings out the open texture and honey colour of natural oak.
This sample shows some unfinished oak that has been silvered by sunlight. This photograph is not black and white - weathered oak takes on a grey colour that can look very dramatic against other finishes. On this piece you can just make out the subtle saw marks on the shaded side of the sample.
Oak that has been planed and oiled has a smooth texture and a lustrous sheen.
Scrub planing is done by hand and gives a smooth finish, while waxing gives a more gentle sheen than that of oiled oak. This sample shows the medullary rays that are sometimes visible in oak.