As far as quality concerns, there have been a lot of different opinions about colour vinyl compared to standard black. Most of the arguments, however, expose a lack of understanding of technicalities and multiple variables that are involved in pressing vinyl records of any colour. Therefore, we decided to explain the most important technical aspects and provide readers with a guide for understanding colour and sound quality dynamics in a process of vinyl record production.
To start with, vinyl records are pressed on a heated thermoplastic material known as polyvinyl chloride or PVC. It’s one of the oldest synthetic materials with a long history in industrial production such as healthcare, IT, transport, textile and construction. The pure, virgin PVC comes in resins of various colours and it is usually mixed with recycled PVC for reducing waste and pressing records more sustainably. Naturally PVC is colorless and colorants are added to obtain colour. For instance, black carbon is added as a colorant in standard black records and different colorants are added to obtain other colours. According to Gunnar Heuschkel from R.A.N.D. MUZIK, in the past some colorants such as titanium oxide in white PVC used to significantly increase background noise levels. But PVC development has come a long way from the times when coloured records were known for their inferior quality. Even though PVC formations may vary from supplier to supplier, most compounding companies today are at the top level.
Pressing records involves critical stages of melting, molding, cooling and trimming that require specific temperatures for an efficient treatment of a PVC compound. The fact that different formations of PVC colours require marginally different temperatures in a manufacturing process is actually the key variable in sound quality on coloured vinyl records. While technically, it is possible to produce equally good sounding records on any colour, from our experience, the lighter colours and colour blends require less heat and a more cautious pressing approach.
Additionally, colour blends prompt inconsistencies in temperature zones on the mold and, if not handled correctly, can easily introduce burn marks, stitches and lead to clicks and pops or other sound artifacts on a record. Hence, the experience and precision of a press operator is crucial in adequately balancing between specific colours, temperatures and sound quality. Furthermore, every vinyl project is special and requires a special approach in production. A unique audio material follows a long line of production stages before the pressing and eventually even the weather conditions may affect how PVC behaves in a press. The behavioural attributes of a certain record in a press are usually learned during test pressings, and that is where the most important adjustments of press settings are taking place.
However, colour vinyl records are also susceptible to a tighter quality control as it is more difficult to identify scratches and other mechanical damages on lighter colours. Another important factor is that black standard PVC is the most widely used compound in vinyl production. That makes it much easier to predict how PVC will behave in a press and hence, easier to work with on a day-to-day basis.
Blending virgin and recycled PVC is a common practice in a record pressing industry. Although regrind should never sound worse than virgin PVC, 100% recycled vinyl from a variety of colours will certainly introduce variations in required temperatures in all stages of manufacturing and may increase noise levels if not handled correctly. Gunnar Heuschkel from R.A.N.D. MUZIK stresses, that it’s important to maintain a very high purity of recycled material because surface noise may rise after several cycles of regrinding due to changes in the length of molecular chains.
In response to recurring questions from our clients and common discussions on internet forums – our experience shows that tracking and other playback issues are not associated with specific colours, but rather are a mastering/master disc cutting error, stamper misprint or pressing inaccuracy.
Our practice proves that PVC colour does not have direct effects on sound quality as material per se, though some colours or colour blends require more sensitive pressing methods where sound quality may or may not degrade. Furthermore, vinyl is naturally an imperfect format and carries multiple sound artifacts such as sustained background noise, clicks and pops, static noise and so forth. In the process of manufacturing, a pressing plant decides what is an issue or a given imperfection and also compromises between the two. The length of a record and the way it’s mastered has a direct impact on volume levels. That may expose or mask the given imperfections and extra noise introduced during the pressing. Some music genres with extended volumes and harsh noise like punk or metal may perfectly mask clicks, pops and background noise. The same applies for quieter musical content such as ambient or classical music, but only from the opposite perspective, where most of the imperfections will be clearly audible.
Due to the nature of audio content, sometimes colours may be compromised for the sound quality or vice versa if specific pressing issues occur during the test pressing. For instance, it can cause certain difficulties to press quiet music on a light colour PVC and either sound or colour has to be compromised. From our experience, some clients prefer visual aesthetics to sound quality and we have to comply with their requests. However, we recommend taking into account the length, volume levels and music genre when deciding on a visual design of your vinyl project and consult your pressing operator for achieving the best quality results. Every pressing plant relies on different methods, for the most part, internally developed, uses different PVC compounds and different presses. And hence, your vinyl quality for the most part will depend on know-how of the company and not the material per se.
When it comes to the production at RPM Records, we recycle as much as possible. We collect all waste records, remove labels, smash, grind and put the recycled material back to a press mixed with 80% virgin PVC. And only rarely we press on 100% recycled material. This applies both to black and coloured vinyl records. In comparison to other pressing plants, we approach and mix colours like paint, hence, we can not produce split or splatter records, but we have an in-house colour expert for developing perfect colour blends. We document recipes for colour blends and store in a database for future use. Because of certain EU regulations for PVC compound, we can not produce clear transparent records and those are available mainly in USA. The most available colours are on our website, and we are always open to experiment with exclusive requests.
As in every other pressing plant, there are some limitations in how smoothly we can transition from colour to colour during the process without completely cleaning out the press. And it is useful to keep in mind, that small orders will have a large part of transitional colours if the colour transition fee has not been included. When approaching coloured vinyl orders, our goals are always to avoid burn marks, harsh colour transitions and to obtain the right colour. However, our first priority is always the sound quality and we take a great precision in achieving that through different pressing temperatures, record cycle times and tight quality control.
Last but not least, RPM team recommends paying great attention to the quality of your master audio file before you submit your music. Loud volumes are less sensitive to background noises and makes it easier to experiment with colours and to guarantee the best sound quality without compromising the visual design. Finally, we advise our readers to see coloured vinyl not as inferior to standard black, but as a different product that may cause extra difficulties in manufacturing.
Enjoy Your Vinyl!