Screen printing, or more commonly referred to as silk screen printing, is one of the many decorating methods utilized to apply ink to a glass or plastic container to develop a picture or pattern by moving ink through an emulsion (stencil) of exposed mesh. The main component involved in creating a screen print image resides in - you got it - the screen! But what makes up the screen itself?
The Screen Frame
The first thing you will notice about a screen (or silk screen) is the frame that gives the screen its form. Depending on the size of the container you will need a screen frame that is big enough to cover the area to be decorated. While both metal (aluminum or steel) and wood frames are in commercial use today, aluminum generally wins greater preference due to its lighter weight and water resistance characteristics. Steel is found useful for bigger printing jobs that require the strength of a steel frame for optimum support. Wood is still utilized commercially, but due to its tendency to warp and deform it has become less prevalent over time.
In our processes, aluminum frames are generally preferred due to its ease of maintenance and its non-absorption properties which make it easy to remove ink after each job. Wood frames tend to absorb water and ink causing it to warp and lose its shape; which reduces the tension (tautness) of the screen. Once the frame has lost its form, it will need to be rebuilt as a slacked screen loses its ability to imprint ink with precision onto the substrate. The slacked screen must be pulled and re-stapled/fastened back onto the frame to regain tension or the entire frame could be unsalvageable.
Now the screen itself…
Silk screening owes it’s origins to the stencil art form from China and Japan dating as far back as 500 A.D. and likely introduced to Europe in the late 18th century. Back then silk was the go-to material for creating the mesh – which is where the term “silk screen” probably came from. Today, modern materials have taken over in the commercial sector with improved durability. Monofilament polyester, multifilament polyester, and nylon are three of the more common types of materials used today. Listed below are some of the more common materials used to make screens:
- Silk - multifilament
- Cotton Organdy - multifilament
- Nylon - multi or mono
- Polyester - multi or mono
- Stainless steel and wire mesh
You may have noticed the term monofilament and multifilament, let’s review what they are:
Monofilament - This type of filament allows for the application of finer detail to a given surface; achieving this application comes from weaving a single thread in a uniform fashion. You can measure this fabric by threads per inch (TPI) or thread count. The greater the thread count, the smaller the openings are for the flow of ink, which allows for sharper and more precise detail. The opposite is true when it comes to a lower thread count that allows for larger openings and more ink to flow resulting in less than fine edges.
Multifilament - Consisting of a thread made up of multiple strands. While lacking the uniformity of the monofilament weave styles, it does offer the added benefit of greater ink deposits and increased adherence to emulsions due to its increased coarseness.
How Long Does a Screen Last?
The life of a screen depends on many factors: type of fabric, frame, frequency of use, and care. Earlier we mentioned how aluminum has advantages over wood frames due to its resistance to corrosion and ease of ink removal, but other factors play equal importance in determining the actual longevity of a screen.
The type of fabric from which the screen is fabricated will play a significant role in its longevity. The use of silk or cotton will result in decreased tension with constant use, therefore decreasing precision, and certain solvents based inks have the ability to destroy silk (and cotton). Polyester is commonly used (mono and multifilament) commercially for its durability and can maintain stability when stretched, delivering an increase in screen life. One of polyester’s greatest strengths lies with its ability to resist solvents; which allows inks to pass through it without chemical abrasion. Stainless steel mesh is the most durable and promotes greater longevity than commonly used fabrics, but it lacks the ability to stretch, which poses a disadvantage.
While a critical component of the decorating process, the screen is just one of the intricate parts of the entire silk screening process. If you have any specific questions surrounding silk screening process, feel free to leave them below.