ULTIMATE COMPATIBILITY GUIDE FOR RECORD FLATTENING
Deeper insights into how different record materials affect the flattening process.
Updated August, 2022
Which records are easy to flatten? Which types of records would not flatten at all? How record material affects the unwarping process? What are some of the unwarping tips shared by experts? How to use the Vinyl Flat for different types of records?
If you're looking to answer at least one of those questions, you've come to the right place. Allocate 5 minutes for the reading, and let's get into the weeds of record flattening.
There are four main types of vinyl records that you're most likely to stumble upon today: Long-Playing Vinyl Records (L.P.), Extended Play Vinyl Records (E.P.), Flexi Disks, and Colored Vinyl Records.
Until the early 1950s, shellac was the most common material with which 78-rpm records were made.
In the second half of the 20th century, most of the records were made of flexible PVC (polyvinyl chloride) compounds.
From around 1951 until 1991, the main material for some records, especially those made in the U.S., was polystyrene (a.k.a. styrene). Some ultra-light records from the 1970s and 1980s also had less vinyl due to the oil embargo.
In addition to those primary materials, records typically include heat stabilizers, lubricants, plasticizers, and colorants. Depending on the base material and combination of supporting materials, some records can be easy or tough to flatten (yes, we finally got to the flattening part).
The more high-grade vinyl is used in the record, the easier it is to flatten it. Some (but not all) colored vinyl may flatten faster than traditional black vinyl. The safest approach for colored records is to use the Vinyl Flat and the Groovy Pouch with decreased initial heating cycle times. For example, if we recommend starting at 2 hours in the pouch at a given temperature, you could start at 1.5 hours, and so on.
Typically, shellac records and styrene records are tough to flatten. But some customers have reported success with 78 RPM shellac recordings. One of our customers found an optimal setting for STYRENE 45s - heating them with the Vinyl Flat and Groovy Pouch from cool to hot to cool again for 2.5 hours at about 140F worked every time. For records that are tough to flatten, we recommend proceeding with extra caution, applying ultra-conservative short heating cycles. It is tempting to raise the temperature and increase the heating cycle right away, but please - resist.
Mobile Fidelity One-Step (MOFI) recordings should flatten like normal vinyl L.P.s because the One-Step process simply eliminates two of the molds that are normally used to stamp the record. And, since a One-Step recording doesn't necessarily contain more or less vinyl than traditional recordings, no special techniques are needed beyond our Vinyl Flat instructions.
In summary, record materials have significant effect on how we should approach the flattening process. The best approach to take is to be conservatively in the beginning, learn and the consistently apply learnings (and then share them with us via our Contact Form - we promise to help the community.