A method of forming an enhanced-surface wall for use in an apparatus for performing a process, comprising the steps of: providing a length of material having opposite initial surfaces (21a, 21b), said material having a longitudinal centerline (x-x) positioned substantially midway between said initial surfaces (21a, 21b), said material having an initial transverse dimension measured from said centerline (x-x) to a point on either of said initial surfaces (21a,21b) located farthest away from said centerline (x-x), each of said initial surfaces (21a,21b) having an initial surface density, said surface density being defined as the number of characters on an surface per unit of projected surface area; impressing secondary patterns having secondary pattern surface densities onto each of said initial surfaces (21a,21b) to distort said material and to increase the surface densities on each of said surfaces (21a,21b) and to increase the transverse dimension of said material from said centerline (x-x) to the farthest point of such distorted material; and impressing primary patterns having primary pattern surface densities onto each of such distorted surfaces to further distort said material and to further increase the surface densities on each of said surfaces (21a,21b); characterized in that the step of impressing said primary pattern onto each of said surfaces (21a,21 b) further increases the dimension from said centerline (x-x) to the farthest point of said further-distorted material; and the step of impressing said primary patterns onto said material does not reduce the minimum dimension of said further-distorted material, when measured from said centerline (x-x) to any point on either of said further-distorted surfaces, below 50% of the minimum dimension of said material, when measured from said centerline (x-x) to either of said initial surfaces (21a,21b); thereby to provide an enhanced-surface wall for use in an apparatus for performing a process. providing a length of material having opposite initial surfaces (21a, 21b), said material having a longitudinal centerline (x-x) positioned substantially midway between said initial surfaces (21a, 21b), said material having an initial transverse dimension measured from said centerline (x-x) to a point on either of said initial surfaces (21a,21b) located farthest away from said centerline (x-x), each of said initial surfaces (21a,21b) having an initial surface density, said surface density being defined as the number of characters on an surface per unit of projected surface area; impressing secondary patterns having secondary pattern surface densities onto each of said initial surfaces (21a,21b) to distort said material and to increase the surface densities on each of said surfaces (21a,21b) and to increase the transverse dimension of said material from said centerline (x-x) to the farthest point of such distorted material; and impressing primary patterns having primary pattern surface densities onto each of such distorted surfaces to further distort said material and to further increase the surface densities on each of said surfaces (21a,21b); characterized in that the step of impressing said primary pattern onto each of said surfaces (21a,21 b) further increases the dimension from said centerline (x-x) to the farthest point of said further-distorted material; and the step of impressing said primary patterns onto said material does not reduce the minimum dimension of said further-distorted material, when measured from said centerline (x-x) to any point on either of said further-distorted surfaces, below 50% of the minimum dimension of said material, when measured from said centerline (x-x) to either of said initial surfaces (21a,21b); thereby to provide an enhanced-surface wall for use in an apparatus for performing a process.