Stainable decorative sheet and method of staining decorative sheet

A stainable decorative sheet comprising:

• a paper base material,
• an adhesive layer formed of a resin and disposed on at least one surface side of the paper base material,
• a nonwoven fabric layer disposed on a surface side of the adhesive layer other than the surface on which the paper base material is disposed, and
• a transparency improving layer formed of a resin and disposed on a surface side of the nonwoven fabric layer other than the surface on which the adhesive layer is disposed,
• wherein the nonwoven fabric layer partially has a filling area A, in which a part of voids of fibers constituting the nonwoven fabric layer is filled with the resin forming the adhesive layer on the side where the adhesive layer is provided in the thickness direction of the nonwoven fabric layer, and a filling area B, in which a part of the voids of the fibers constituting the nonwoven fabric layer is filled with the resin forming the transparency improving layer on the side where the transparency improving layer is provided in the thickness direction of the nonwoven fabric layer,
• wherein the nonwoven fabric layer is a single nonwoven fabric layer,
• wherein the resin forming the adhesive layer contains a urethane resin, and
• wherein a wetting tension of the urethane resin in the adhesive layer is 70 mN/m or more.