MFSL Master Sleeves HeavyWeight Edition - LP inner sleeves - 50 pieces

The most valuable record in your collection can be permanently damaged by a bad inner sleeve - and it happens slowly and invisibly. Paper sleeves, which most LPs come with from the factory, scratch the vinyl surface with micro-abrasive particles when they are taken in and out. They become statically charged and draw dust directly onto the grooves when the record is pulled out. Over time, they release acid and plasticizers that can chemically attack the vinyl. The Mobile Fidelity Sound Lab Original Master Sleeves are the answer to this - the recognized industry standard for audiophile vinyl archiving for over 40 years and still the reference against which all other inner sleeves must be measured.

Mobile Fidelity Sound Lab (MoFi) is the most renowned audiophile record label in the USA - known for its Half-Speed Mastered and UltraDisc One-Step pressings on 200-gram vinyl, which are regularly ranked among the best-sounding vinyl releases in the world. For decades, they have developed and used the same sleeves for their own pressings, which are now also available individually: the Original Master Sleeves. Anyone who owns MoFi records already knows them. If you want to protect your entire collection at this level, you can find them here in a pack of 50.

The MFSL Master Sleeves consist of three functional layers. The back consists of two layers of high-density polyethylene (HDPE) with a layer of paper laminated between them. This construction gives the sleeve dimensional stability and pleasant handling properties - the plate slides in and out smoothly without losing the precision of a rigid sleeve. The front is made of translucent HDPE - thin enough to make the plate label and matrix numbers legible without having to remove the plate. This makes archiving and identification much easier.

The decisive difference to simple paper sleeves lies in the material itself: HDPE is non-abrasive - it leaves no micro-scratches on the vinyl surface when the record is pulled in or out. Paper, on the other hand, contains microscopic fibers that abrade the delicate groove surface with every contact. Over hundreds of plays, this effect adds up to visible and audible surface degradation. HDPE is also acid-free - it does not release any aggressive chemicals into the vinyl that could make the material brittle in the long term.

Static electricity is one of the most common - and least recognized - enemies of vinyl collections. When a record is pulled out of a conventional paper sleeve, an electrostatic charge builds up due to friction. This charge draws dust particles from the air directly onto the surface - and into the grooves. The effect is immediately audible: more noise, more crackling, more distortion. The antistatic formulation of the MFSL Master Sleeves prevents this charge from building up as soon as the record is pulled out. The Absolute Sound describes it aptly: "The MoFi sleeves are renowned for their antistatic properties, which prevent dust and dirt from being drawn into the sensitive grooves.

For an optimum chain of action, it is advisable to insert cleaned records - ideally after treatment with a record cleaner or after ultrasonic cleaning - into fresh MFSL Master sleeves. The combination of a clean groove and an anti-static, non-abrasive sleeve is the most effective long-term protection for any vinyl collection.