Method of making light-blocking articles

A method for providing a foamed, opacifying element, the method consisting essentially of:

• A) providing a foamable aqueous composition that has at least 35% solids and up to and including 70% solids, and consists essentially of:
• (a) at least 0.05 weight % and up to and including 15 weight % of porous particles, each porous particle comprising a continuous polymeric phase and discrete pores dispersed within the continuous polymeric phase, the porous particles having a mode particle size of at least 2 μm and up to and including 50 μm;
• (b) at least 20 weight % and up to and including 70 weight % of a binder material having a glass transition temperature (Tg) of less than 25° C.;
• (c) at least 0.0001 weight % and up to and including 30 weight % of one or more additives comprising a surfactant;
• (d) water;
• (e) at least 0.001 weight % of an opacifying colorant different from all the one or more (c) additives, which opacifying colorant absorbs electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm,
• all amounts based on the total weight of the foamable aqueous composition;
• B) aerating the foamable aqueous composition to provide a foamed aqueous composition having a foam density of at least 0.1 g/cm3 and up to and including 0.5 g/cm3;
• C) disposing the foamed aqueous composition onto a first opposing surface of a substrate also having a second opposing surface;
• D) drying the foamed aqueous composition, without substantial curing of the binder material, to provide a dry foamed composition on the first opposing surface;
• E) densifying the dry foamed composition;
• F) curing the dry foamed composition to convert the (b) binder material to a (b′) matrix material,
• wherein E) densifying and F) curing can be carried out in the indicated order or in the opposite order, to provide a foamed, opacifying element having an opacifying layer, and
• wherein, at any time after D) drying, the method further comprises
• G) disposing a functional composition onto either the dry foamed composition or the opacifying layer, and drying the disposed functional composition,
• the functional composition comprising either or both of:
• (i) inorganic or organic spacer particles having a mode particle size of at least 1 μm and up to and including 100 μm, and which inorganic or organic spacer particles resist melt flow at a pressure of up to and including 100 psi (689.5 kPa) and a temperature of up to and including 220° C.;
• and (iii) a tinting material comprising one or more pigments, one or more dyes, or a combination thereof, wherein the (i) inorganic or organic spacer particles and the (iii) tinting material are different materials.