How Does Emulsion Work?

Promo Expert

Published: May 11th, 2020

Emulsion is an extremely fascinating printing process for branding promotional products. We'll break it down and explain what exactly emulsion involves and how it relates to the promo industry. Get ready to put your thinking caps on and dive into the world of emulsion!

To put it simply, emulsion is a substance that's used in screen printing to get a logo on promotional products. The actual process is known as photographic emulsion, and it's been around for a long time. In fact, it was used back in the day to develop photographs.

What's an Emulsion?

Basically, photographic emulsion is a colloidal suspension of liquid within another liquid. In other words, photographic emulsion is more of a gel-like substance rather than a substance that's totally liquid. It typically contains silver halide crystals, which disperses evenly throughout the gel.

The silver halide crystals, which are light-sensitive, rest in the gelatinous material; they can be incorporated onto a variety of mediums such as paper, plastic, fabric, or glass during the manufacturing process. In photographs, the silver halide reacts to the chemicals used in the film developing stage, which produces the image from the film on the photograph paper. It's a slightly different process when it comes to promotional products.

The Skinny on Emulsion

The emulsion gel is spread over both sides of a mesh screen that will be used to transfer the logo onto the promotional item. Prior to the emulsion drying, your logo is printed onto the emulsion-covered mesh screen. This is done either with a super special UV-blocking ink, or with clear acetate. Acetate is a thin film sheet that is used in a variety of different ways – including in baking!

Both of these methods block UV waves, which is important because after your logo is applied to the screen, it goes under a UV light. When the emulsion is exposed to UV light, it hardens, except for where your logo is printed. The emulsion gel is still soft in the area that was protected from the UV light. This makes it easy to wash away, leaving a negative imprint of your logo. All that's left after that is to spread ink onto the screen, which is then pressed through the logo and onto the promotional product.

See emulsion in action with our video here!

Photography and Emulsion

The emulsion process actually played a role in how the camera company Kodak was formed. George Eastman, who made the first camera in 1887, put an emulsion onto a plastic-like material eventually known as 'film' and enclosed it in a camera (which is why you aren't supposed to expose film to light before developing it – remember, silver halide crystals are sensitive to light!). Eastman's company would take the camera, develop the film, and return the pictures back to the customer. It was called the Kodak system!

Eventually with the advancement of developers, you could have your film ready to go in under an hour. However, with the advent of digital photography, and those smartphone cameras that continue to improve exponentially with each new generation, the use of photographic emulsion to print pictures isn't as popular anymore.

However, the emulsion process is still one of the most effective ways to imprint logos onto promotional products. Emulsion is great for tote bags, but it also works for round products such as tumblers or pens.

You can find all of our promotional products available for screen-printing with the emulsion method on the Quality Logo Products website. Check them all out now!

Who knew that the emulsion process is used to develop photos? It might not be as popular for photos today, but it's important to the promotional products industry. Screen printing is a very popular imprint method simply because it works on many different surfaces like pens, t-shirts, and tumblers. We may not use it for our digital cameras, but it's a great way to display your fantastic logo!