Sikkens Cetol Filter 7 plus Dark Oak is a low-build, solvent-borne, semi-transparent wood stain for use on exterior softwood and hardwood substrates such as cladding, fascias, soffits, rough-sawn timber, fencing, or components subject to high levels of wear and abrasion, such as garden furniture, handrails and exterior decking. It is applied as a base stain before applying higher build finishes such as Cetol Filter 7 plus or Cetol THB plus on smooth planed exterior joinery. It plus should not be used alone as a finish for hardwood timbers other than decking.