The causal formula for vinyl deformity is (Heat > 70 degrees F+ Uneven pressure across a recrd’s surface) / Time.
IOW: The vinyl substrate on which records are pressed softens in direct proportion to exposure to temperatures >70º Fahrenheit. The duration of their exposure is inversely proportional to the temperature elevation that softens vinyl to the same extent.
Record warping is a process that begins when heat softens the vinyl enough to deform during the simultaneous application of uneven pressure across a record’s surface. This uneven pressure occurs when records lean to one side. The higher the temperature, and/or the greater the uneven pressure, the less time it takes a deformity to develop.
The closer one edge of a record’s proximity to a home heating source, the greater the tendency for an isolated edge deformity to develop. Edge warps cause phonograph styli to skip or repeat playback of a record’s outer grooves. An edge warp that extends far enough toward the record’s center can render the introductory portions of the recorded music unplayable. Severe edge warps under the influence of modern anti-skating mechanisms can toss a playback off the edge of the record. Most edge warps are irreparable.
“Dish” deformities develop when an entire record is exposed to heat while the angles at which they lean are great enough to form pressure voids over a substantial portion of a record’s large midsection.
Dish warps decouple a record from the turntable platter when they’re played. This phenomenon allows the record’s inherent resonance to color the sound listeners hear—differing in intensity with each record rotation. This, in turn, has a deleterious effect on the fidelity that leads music lovers to choose vinyl records because of their extraordinarily high fidelity to the music’s source. The good news is that dish warps are repairable, as described by Sumiko
Either deformity becomes set when a deformed record cools. Repeated heating/cooling cycles “ratchet” up the warp’s severity over time until listeners finally notice it. The bad news is that in most cases, the process is so insidious that the process goes unnoticed until it’s too late to prevent it.
The good news for you, SOIX is that per your description, your record collection hasn’t been subjected to temperatures >70 degrees F while they’ve been stored as you’ve described. So unless they were subjected to temperatures > 70 degrees F at the same time they were exposed to uneven surface pressures before you began storing them as you’ve described, I can assure you that your valuable and sometimes irreplaceable records are not warped.
Look for Diamond Record Guardian, LLC to introduce its failsafe warp prevention system at the beginning of July.