How to Dye Acrylic Plastic

Acrylic Plastic

Acrylic plastic—both in extruded and cast forms—contributes a unique beauty to jewelry and sculpted art and décor.

In this article, I will discuss the various steps and techniques in dyeing acrylics to create something even more spectacular, including the following:

• materials needed
• safety concerns
• use of dye carriers
• the methods of dyeing clear acrylic plastic
• examples of work from other creators featuring dyed acrylics

Why Dye Plexiglass and Acrylic Plastic?

If you do an online search for acrylic sheets or Plexiglass, you will find that it comes in many sizes, thicknesses, and even textures. Also, acrylic sheets can be found in several colors that are transparent, translucent, mirrored, or opaque. So why would anyone want to deal with the hassle and mess of trying to dye clear acrylic plastic?

• The dyes can be mixed in any proportion to produce an almost infinite array of colors.
• By controlling dye concentration, heat input, and immersion time, you can dial in the necessary intensity of color to a point.
• Clear acrylic is cheaper than colored and available in many thicknesses.
• It is possible to partially immerse objects to create interesting decorative coloring.

Tools and Materials Needed

Most of the tools and materials needed to dye acrylic can be found around the home or easily obtained from local stores.

• Disperse dye specifically made for synthetic materials
• Portable hot plate
• Stainless steel pot, an enameled pan, or a Pyrex glass container that is no longer used for food preparation
• Thermometer
• Stirring rod
• String or pliers to remove the dyed workpiece
• Isopropyl alcohol
• Acetone
• Selection of extruded or cast acrylic parts

Safety and Cleanliness

Safety is an important subject to cover here. Although most of the dispersed dyes are relatively non-toxic, they can be very messy and may permanently stain many materials.

Other types of dyes, namely basic dyes, carry a significant hazard as they are even more tenacious in staining and are considerably more toxic. Always wear gloves when dyeing and thoroughly clean all tools and materials with warm soapy water.

The real safety concern here is the use of isopropyl alcohol and acetone. We will be using a small amount in heated water-based dye baths, and good ventilation is essential.

Fire Hazard Reminders

• Both Acetone and Isopropyl alcohol are flammable. Acetone is much more so!
• Never leave the heated dye bath unattended.
• Never let the bath boil to the point it froths over the walls of the container. If necessary, remove it from the heat source if things get out of hand.
• If the bath ignites, calmly cover it with a fireproof lid and remove it from the heat source
• This process should only be done outdoors or in a very well-ventilated space far away from flammable surfaces or open flames.

What Are Disperse Dyes?

Disperse dyes are neutral organic dyes that feature no ionic bonding groups. They are generally water-insoluble. Therefore, they are "dispersed" in water with a surface-active detergent to create an emulsion.

By heating the bath to 185-212 degrees Fahrenheit and using a carrier, the acrylic plastic surface can swell and accept the dye. Since the dye is not really soluble in water, it is easily transferred to the synthetic particles within the acrylic.

Role of Dye Carrier

As noted above, disperse dyes are not soluble in water and usually need a detergent to help keep them dispersed in water.

The dye carrier is an organic liquid that is soluble in water and can better dissolve the dispersed organic dyes. Also, the carrier opens the pores of the acrylic plastic enough to assist in setting dye in the acrylic.

The carrier is chosen to be a solvent strong enough to have action on the acrylic but not so much that it crazes or melts the plastic. It is best to add a carrier to a dye bath prior to heating or the carrier may flash boil violently out of the container.

How to Dye Acrylic Plastic

1. Pick the smallest stainless, enameled pot or Pyrex glass container that will hold enough fluid to cover your acrylic object completely.
2. Use a measuring cup to determine the volume of dye bath needed to cover the part.
3. Once the volume of the bath is determined, mix water to dye in a 3:1 ratio (e.g., 300 ml water to 100ml water).
4. Add carrier (isopropyl alcohol or acetone) in a quantity that is 25 to 30% volume of dye and water mixture.
5. With a thermometer in the bath, gently heat the bath until it reaches 185 degrees Fahrenheit (85 degrees Celsius). The carrier will already be boiling out of the solution at this point. Immerse acrylic and keep agitated.
6. When proper color intensity is obtained, remove from the bath and rinse in cool water.

Tips and Tricks

• Extruded acrylic dyes are easier than cast acrylic.
• Some dyes can tint lightly without carrier if a subtle color is desired.
• To increase color intensity, prolong immersion into the dye bath or add more dye.

Suggested Liquid Dye Bath Compositions

Dye Solution	Temperature for Dyeing	Carrier
1 part liquid RIT Dyemore and 3 parts water	200 degrees Fahrenheit +	Isopropyl Alcohol 30% by volume
1 part liquid RIT Dyemore and 3 parts water	185 degrees +	Acetone 25% to 30% by volume

Guidelines to help formulate dye baths for acrylic plastics

Using Basic Dyes on Acrylic Glass

So far, I have been focused entirely on dispersion-type dyes in liquid form. Even though these dyes can only produce light or, at best, medium tinting of acrylic sheets or blocks, using liquid disperse dyes is the easiest and safest method for beginners. If you are well organized and make safety a priority, then you should be able to use basic dyes for the darker and more intense coloring of clear acrylic plastic.

What Is a Basic Dye?

It is a dye that has a molecule that is positively charged, unlike acid dyes which use a negatively charged molecule. What this basically means is that basic dyes are very active and will dye many things other dyes would not. They are usually supplied in powdered form and require special handling because of this. Also, some basic dyes are toxic and/or may increase the risk of cancer. This is where personal protective equipment and safe practices come into play. Protective eyewear and a dust mask are the minimum protective measures needed.

It is best to have a dedicated place for handling this dye, so nothing important gets permanently stained. This can be a garage or shed with newspapers or drop cloth on the floor to collect any solid or solution that spills.

For deep or intense colors, 4-5% by weight of the Plexiglas to be dyed is used. Some basic dyes may not dissolve easily in even hot water, so vinegar must be used.

Room Temperature Dyeing of Clear Cast Acrylic

Dyeing clear acrylic can be a fun and creative way to add color to your projects or crafts. One popular method is to use a mixture of acetone and liquid RIT disperse dye in a 4:3 by volume ratio at room temperature. This technique can be used to achieve vibrant, long-lasting colors on acrylic surfaces.

Instructions

1. To start, make sure that your clear acrylic is clean and free of any dirt or debris.
2. Next, mix the acetone and liquid RIT disperse dye in a 4:3 ratio by volume. The acetone will act as a solvent to help the dye penetrate the acrylic surface. (Note: that acetone is a flammable solvent, so be sure to take proper safety precautions, such as working in a well-ventilated area and avoiding open flames or sparks.)
3. Once the dye mixture is ready, immerse the acrylic piece in the dye, and allow it to soak for several minutes or until the desired color is achieved.
4. Agitate the acrylic piece periodically during the dyeing process to ensure even color distribution. Also, you might have to strain the dye mixture after acetone is added because acetone reduces the solubility of some solids.
5. After dyeing, rinse the acrylic thoroughly with water to remove any excess dye, and allow it to dry completely before handling or using.

With proper technique and care, dyeing clear acrylic with a mixture of acetone and liquid RIT disperse dye can yield beautiful, long-lasting results.