A tape-type magnetic recording medium, includes a substrate; and a magnetic layer provided on the substrate. The magnetic recording medium is configured such that (1) (w.sub.max−w.sub.min)/w.sub.min≤400 [ppm] where w.sub.max and w.sub.min are respectively maximum and minimum of average values of width of the magnetic recording medium measured under four environments whose temperature and relative humidity are (10° C., 10%), (10° C., 80%), (29° C., 80%), and (45° C., 10%), respectively, and the magnetic layer has a squareness ratio of 65% or more in the vertical direction, and (2) 4.4≤T.sub.B/(T.sub.A−T.sub.B) where T.sub.A is an average thickness of the magnetic recording medium and T.sub.B is an average thickness of the substrate.

In one general approach, a product includes an underlayer of a magnetic recording medium. The underlayer has encapsulated nanoparticles each comprising a magnetic nanoparticle encapsulated by an aromatic polymer, and a polymeric binder binding the encapsulated nanoparticles. A magnetic recording layer is formed above the underlayer. In another general approach, a product includes an electrically conductive underlayer of a magnetic recording medium. The underlayer has encapsulated nanoparticles each comprising a magnetic nanoparticle encapsulated by an aromatic polymer, and a polymeric binder binding the encapsulated nanoparticles. A magnetic recording layer is formed above the underlayer. The magnetic nanoparticles have an average magnetic field strength of less than 200 Oersted (Oe). An average concentration of the encapsulated nanoparticles in the underlayer is at least 35 vol %.

A product, according to one approach, includes a recording layer. The recording layer includes encapsulated nanoparticles each comprising a magnetic nanoparticle encapsulated by an encapsulating layer. A polymeric binder binds the encapsulated nanoparticles. A product, according to another approach, includes a recording layer. The recording layer includes encapsulated nanoparticles each comprising a magnetic nanoparticle encapsulated by an encapsulating layer, and a polymeric binder binding the encapsulated nanoparticles. An average diameter of the magnetic nanoparticles is in a range of 2 nanometers to 20 nanometers. An average thickness of the recording layer is less than 0.2 microns.

A product, according to one approach, includes an underlayer and a magnetic recording layer formed above the underlayer. The underlayer includes first encapsulated nanoparticles each comprising a first magnetic nanoparticle encapsulated by a first aromatic polymer, and a first polymeric binder binding the first encapsulated nanoparticles. The recording layer includes second encapsulated nanoparticles each comprising a second magnetic nanoparticle encapsulated by an encapsulating layer, and a second polymeric binder binding the second encapsulated nanoparticles.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or greater than 5.5.

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or less than 3.8.

A method for forming a printed material includes forming an image on a recording medium; applying particles to a surface of the recording medium, the surface having the image formed thereon; heating the particles applied to the recording medium; and pressurizing, in a thickness direction, a multilayer body obtained by folding the recording medium so that the heated particles are sandwiched between flaps of the recording medium or a multilayer body obtained by placing another medium on top of the recording medium with the heated particles therebetween. The particles contain a styrene resin and a (meth)acrylic acid ester resin. The (meth)acrylic acid ester resin contains two (meth)acrylic acid ester monomer units, and a mass ratio of the (meth)acrylic acid ester monomer units relative to a total of polymerization components is 90 mass % or more.

In a magnetic recording medium, an average thickness t.sub.T is t.sub.T5.5 m, a dimensional variation w in a width direction to tension change in a longitudinal direction is 650 ppm/Nw, and a rate of shrinkage in the longitudinal direction is 0.08% or less.

In a magnetic recording medium, an average thickness t.sub.T is t.sub.T5.5 m, a dimensional variation w in a width direction to tension change in a longitudinal direction is 650 ppm/Nw, and a rate of shrinkage in the longitudinal direction is 0.08% or less.

A tape-type magnetic recording medium, includes a substrate; and a magnetic layer provided on the substrate. The magnetic recording medium is configured such that (1) (w.sub.maxw.sub.min)/w.sub.min400 [ppm] where w.sub.max and w.sub.min are respectively maximum and minimum of average values of width of the magnetic recording medium measured under four environments whose temperature and relative humidity are (10 C., 10%), (10 C., 80%), (29 C., 80%), and (45 C., 10%), respectively, and the magnetic layer has a squareness ratio of 65% or more in the vertical direction, and (2) 4.4T.sub.B/(T.sub.AT.sub.B) where T.sub.A is an average thickness of the magnetic recording medium and T.sub.B is an average thickness of the substrate.