Iddings Deep Colors FAQ's

What is Iddings Deep Colors?

Iddings Deep Colors has been preferred by scenic artists for more than 50 years. But there are hidden difficulties that you must understand in order to successfully work with Iddings Deep Colors.

Paint is made up of three components, pigment, binder and medium. Pigment is, as you might guess, the colorant. Medium simply allows the pigment and binder to mix properly. In all Rosco paints, the medium is water. Binder, as the name implies, controls how well the paint adheres to different surfaces, how durable the paint will be when it has dried, and how flexible that dry coating will remain over time. The Iddings Deep Colors line uses a casein binder. It is this casein binder that creates many of the challenges associated with Iddings Deep Colors.

Painting with casein paint

Casein is a traditional binder that has been used in paint systems for hundreds of years. It is a milk protein, unlike the inorganic latex, vinyls, and acrylics that are commonly used in modern paint formulations.

Advantages of a casein binder:

  • Iddings Deep Colors provides the most matte, non-reflective paint finish available.
  • It has superior adhesion on porous surfaces like muslin, scrim and canvas and remains extremely flexible.
  • Iddings Deep Colors can be reconstituted.

Disadvantages of a casein binder:

In order to get proper adhesion on non-porous surfaces, the casein binder needs clear acrylic added to it. Since casein is an organic substance, it will spoil over time and with the introduction of bacteria from dirty wet utensils and water sources. Thinned out paint will spoil faster than the concentrated paint in the can.

The re-wettability and spoiling of Iddings Deep Colors cause most of the difficulties that painters encounter.

What is the most effective use for Iddings Deep Colors?"

Iddings Deep Colors is an excellent choice for painting soft goods. It has a completely matte finish and allows drops to stay supple. It also has excellent opacity due to the pigment load. For additional adhesion add Rosco Clear Acrylic Glaze to Iddings Deep Colors.

Working with reconstituting the painted surface.

Reconstituting means that the paint film will react with water even after it has dried. In other words, if you put down water, or anything that contains water (like wet paint) on top of dried Iddings Deep Colors, the dry paint film below will re-solve and become wet paint. So if you brush down a layer of yellow paint on top of a dry layer of blue Iddings Deep Colors, the wet yellow will cause the blue to "re-wet" and the two will mix and bleed together to form green.

Many painters use this feature of Iddings Deep Colors to their advantage, planning their painting techniques to take full advantage of the ability to wet blend color effects.

In film and television, scenic artists will often use Iddings Deep Colors to paint props or furniture that must be restored after filming. By painting them with Iddings Deep Colors, these pieces can be washed down when properly prepared with clear water and restored to their original state. Likewise, Iddings Deep Colors can be used to put down sophisticated faux finish floor treatments which can be easily removed. Using a water hose and floor buffing machine, the floor can be restored. This is particularly useful in television studios that have restrictions against painting the floor.

However, if the reconstituting is not desired, there is a simple solution. By adding Rosco Clear Acrylic Glaze (flat or gloss) directly into the Iddings Deep Colors (approximately 1 cup to the gallon) you can stabilize the casein binder and prevent the dry paint from re-wetting. This is very helpful if you are laying down many thin paint glazes or you may "isolate" the paint treatment by lightly spraying 2 or 3 coats of the Clear Acrylic Glaze on top to seal the paint.

How to preserve casein paint?

Anyone who has ever been subjected to the smell of rotted casein knows that this next subject should not be taken lightly. Casein is an organic compound. Like a container of milk which can be made to last longer by adding preservatives to it, careful storage, and proper climate control are ways of extending the shelf life of Iddings Deep Colors.

Iddings Deep Colors contain a powerful anti-bacterial agent as a preservative against premature spoilage. Until recently, the most common, and most powerful preservatives used in water-based paints were mercury based biocides. Several years ago, the Environmental Protection Agency made sweeping changes to regulations affecting the Paint and Coatings industry and banned mercury based biocides. While this was a good change for health and safety concerns, it has made casein paints more vulnerable to spoiling since few biocides are as strong as the mercury based products. Rosco now uses one of the strongest preservatives available in the manufacturing of Iddings Deep Colors that is not mercury based.

Another result of changing biocides is that our current preservative does not have some of the odor masking properties of the previous preservative. Certain pigments naturally give off a musky, earthy smell, notably the blues and blacks. While not necessarily pleasant, this smell is not rotted casein. To compensate, some Iddings Deep Colors have had a pine oil type compound added as an odor mask.

There are several steps that you can take to extend the life of your Iddings Deep Colors. Remember that casein is a milk based protein. So the steps you take to keep your milk from spoiling will help to preserve Iddings Deep Colors.

Though often it is difficult to accurately control the temperature where paint is stored, cool, dry storage areas are best. When possible keep the paint below 70° F (21° C) and above 55° F (13° C) .

Iddings Deep Colors is concentrated. The project being painted today may need only a quart or so. Next week's backdrop another pint etc. Only dilute the amount you're going to use right away. Take a portion of the concentrated paint out of the can, tightly re-seal the container, and add water only to the portion you've decanted. Water contains bacteria that will feed on the casein, causing the spoilage.

Water also upsets the balance of preservative in the paint. The preservative is in proportion to the amount of solids in the paint. Over time, diluted paint has a greater likelihood of spoiling as there is less preservative in proportion to the total volume of paint. Once the paint has dried, and the water has evaporated, the balance is restored and the preservative prevents the dried paint from spoiling. ONCE WET PAINT SPOILS, YOU CANNOT USE THE PAINT AND ASSUME THE SMELL WILL DISPERSE AFTER THE COATING HAS DRIED. The smell will not go away and there is nothing that can be done to remove it.

Another trick for extending the shelf life of Iddings Deep Colors is to add a commercial anti-bacterial product like pine oil right into the paint can. Simply add some of the liquid to the top of the paint, allowing it to sit on top. When it sits on top of the paint, it further prevents the likelihood of airborne contaminants and can later be poured off.

Can I use Iddings Deep Colors once it has spoiled?

NO! Many believe that once spoiled Deep Colors dries the smell vanishes. It does not. The smell with stay forever.

Can I use Iddings Deep Colors once it has frozen?

Yes. Allow the paint to return to room temerature and use it as you normally would. You may find that the product needs less thinning, however.


Shelf life and determining the age of Roscopaint stock

Shelf life varies based on factors too numerous to control but there are a few generalities you can depend upon. Minimum shelf life for unopened, sealed paint is approximately 24 months when stored in a temperature controlled location. Once the can has been opened, if no water is introduced, and the can is properly re-sealed, expect 6-12 months of shelf life. Diluted paint may last for up to 3 months, though MANY factors can shorten or lengthen this estimate. Always use a clean, dry utensil to scoop paint from the container. This will keep bacteria from being introduced to the paint.

Additional Guidelines

Iddings Deep Colors is a superior paint to work with and can yield stunning scenographic results. With some care in handling, it can be a problem free product as well. Just the small amount of information in this note can prevent the most common problems.

Of course, another solution to spoiled casein is to switch to an acrylic system like Rosco Supersaturated or Off-Broadway. These versatile vinyl acrylic binders offer excellent painting qualities and will not spoil. Please contact Rosco for more information on those and other Rosco Scenic products.