Films for use as interleaves between substrates

A film for use as an interleaf between substrates, the film comprising:

• a first side having a first micro-embossed surface and a first formed pattern;
• a second side having a second micro-embossed surface and a second formed pattern;
• a basis weight of between about 35 gsm and about 80 gsm;
• a Low Load Thickness of between about 150 micrometers and 400 micrometers according to the Low Load Thickness Test;
• and
• a flexural stiffness of between about 150 grams and about 500 grams according to the Circular Bend Stiffness Test,
• wherein the first formed pattern and the second formed pattern are complementary to each other,
• wherein the first formed pattern comprises a plurality of first peaks and a plurality of first valleys extending in a first direction, wherein the first peaks alternate with the first valleys in a second direction, perpendicular to the first direction,
• wherein the second formed pattern comprises a plurality of second peaks and a plurality of second valleys extending in the first direction, wherein the second peaks alternate with the second valleys in the second direction,
• wherein each first peak on the first side of the film is opposite to a second valley on the second side of the film, each first valley on the first side of the film is opposite a second peak on the second side of the film, and a cross-section of the film taken along the second direction has an undulating configuration, and
• wherein the interleaf is removable from between the substrates.