Baselayr makes emulsion simple. Instead of looking at 10 or 20 different emulsions, Baselayr offers three to select from. It’s much easier for a printer to decide which emulsion would work best for their print shop. This article will outline the four factors that determine which emulsion will best fit a shop’s needs and environment.
DIAZO VS. PRESENSITIZED
Before picking an emulsion, it’s important to know that there are two types of emulsion — diazo-mixed and presensitized.
Diazo-mixed emulsions need diazo powder mixed into it before printing. The diazo activates or sensitizes the emulsion. The Long Lasting Emulsion is a diazo-mixed emulsion. Diazo emulsions take longer to expose, but are more forgiving. Diazo emulsions are best for new printers or people who do not have exposure units with LED, timers, or vacuum lids. They’re user-friendly, thanks to its ability to be washed out under UV light (as long as the stencil is wet). They’re also cheaper, but they still maintain detail and quality.
Presensitized emulsions arrive ready to be used (no mixing any additive required). Examples of presensitized emulsions are Baselayr Plastisol and Complete. Presensitized emulsions expose quickly and capture fine detail. The only caveat is that these types of emulsions are highly sensitive. Printers with a good grasp on the darkroom and coating screens should be able to use this emulsion with ease. It’s best to have an exposure unit with a timer and vacuum lid as well.
EXPERIENCE LEVEL
Beginners should use diazo-mixed emulsions. It’s user-friendly and forgiving. Since it takes longer to expose, you have a larger window of error from exposing issues or light leakage. It’ll still perform in less-than-ideal darkrooms or exposure units.
Printers who consider themselves at the intermediate level will need to take a look at their darkroom environment and skills. If they have an LED vacuum lid exposure unit and a light-safe darkroom, they could start experimenting with presensitized emulsions. While they experiment and build a SOP, it’s a good idea to use diazo emulsions for orders to keep production running smoothly.
Advanced printers can use whatever emulsion they want. Their darkroom is optimal (no light leakage, it’s warm and dry, has top-of-the-line equipment, etc.) and they excel at coating, drying, and exposing screens. Most advanced printers would use Baselayr Complete, especially since there’s an option to add in diazo if they need better durability or higher image resolution.
DARKROOM ENVIRONMENT
An optimal darkroom has the following features:
- Light-safe
- Dry and warm
- LED exposure unit with a timer and vacuum lid
- Washout booth
- Screen racks
- Dehumidifier
- Hygrometer
- Fans with filters
If a printer’s darkroom is set up correctly, then they can use any kind of emulsion.
Printers working out of a darkroom in their spare bedroom, garage, closet, or bathroom have a higher chance of light entering the room. To avoid prematurely burning screens, use diazo-mixed emulsions.
EXPOSURE UNIT
The exposure unit and its features also determine which emulsion will perform the best. Printers using a single bulb, a lidless exposure unit, or a unit that doesn’t have LED need to use diazo mixed emulsions like Long Lasting. They’re more forgiving and easier to work with.
Printers with an LED exposure unit with a vacuum lid can use any type of emulsion. The vacuum lid creates tight, positive contact between the glass, film, and emulsion. Having tight, strong contact to the point where the black ink on the film is almost embedded into the emulsion means that light has difficulty wrapping around the film. Since vacuums inhibit light wrapping around the film, both presensitized and diazo-mixed emulsions will work.
TYPE OF INK
Lastly, but just as important, the type of ink the printer is going to use will help dictate which emulsion they should use. Some emulsions work for all ink types while some work with specific inks. When printing water-based ink, use Baselayr Complete or Long Lasting. When printing plastisol ink, use Baselayr Complete, Long Lasting, or Plastisol. For discharge and solvent-based ink, use Complete.
The darkroom environment, a printer’s skillset, exposure unit, and types of inks used gives a printer all the information they need to know exactly which emulsion they should grab off their shelf.