Plastic bag with sealable slidable zipper

A plastic bag comprising:

• a first panel;
• a second panel, the first panel and second panel defining a bag interior and an opening at an end margin of the first and second panels to permit access to the bag interior;
• and
• a closure at the opening comprising first and second mutually interlocking profiles on the first and second panels, respectively, the interlocking profiles comprising;
• a first profile vertical sidewall and a second profile vertical sidewall;
• multiple projections extending laterally from the first profile sidewall toward the second profile vertical sidewall and multiple projections extending laterally from the second profile sidewall toward the first profile sidewall, the multiple projections comprising:
• a hook-shaped first closure projection on the first interlocking profile which interlocks with a hook-shaped first closure projection on the second interlocking profile when the closure is engaged;
• a sealing projection on the first interlocking profile opposite a sealing channel on the second interlocking profile, and a sealing projection on the second interlocking profile opposite a sealing channel on the first interlocking profile;
• and
• a second closure projection on the first interlocking profile which interlocks with a second closure projection on the second interlocking profile when the closure is engaged;
• wherein each of the multiple projections consists of a base portion abutting the sidewall from which it projects, a central body portion, and a tip portion;
• and
• wherein for the sealing projection on the first interlocking profile and exactly one of either the first closure projection or the second closure projection on the first interlocking profile, the base portion abutting the sidewall from which it projects, the central body portion, and the tip portion constituting the entirety of the sealing projection on the first interlocking profile and the exactly one of either the first closure projection or the second closure projection on the first interlocking profile are extruded from a plastic material which is different from and softer than a more rigid plastic material from which all of the other projections on the first and second interlocking profiles are extruded, such that the sealing projection on the first interlocking profile and the exactly one of either the first closure projection or the second closure projection on the first interlocking profile consist of the softer material.