Stockholm tai is obtained during the manufacture of charcoal from pine wood. It is a good preservative for woodwork, being better than coal tar for the purpose. It can be thinned with creosote oil or coal-tar naphtha, or with wood spirit. Swedish pitch may be melted and the tar stirred into it for thickening purposes. It is, perhaps, best to apply the tar hot, because heat expands the cells of the wood, and the subsequent contraction causes the tar to be drawn into the wood. Swedish pitch is simply the tar heated until the liquid volatile portions have distilled over.