Screen Printing
Screen printing pushes ink through a stencilled mesh onto the surface below, laying down one opaque color per pass.
- Part
- Finishing
- Revised
- 2026-08-11
At a glance
- Family
- Printing
- Typical tolerances
- Registration typically ±0.005–0.010 in (±0.13–0.25 mm); dried ink film 0.0004–0.002 in (10–50 µm), which is enough to matter on a stacked assembly
- Surface finish
- Matte through gloss depending on ink; the heavy film gives a slightly raised, tactile edge on solid areas
- Typical volumes
- A hundred to millions of impressions; setup per color makes very short runs uneconomical
- Lead time
- 1–2 weeks including screens and setup; 3–7 business days for repeat orders
- Materials
- Plastic, Metal, Glass, Wood, Ceramic
What it is
Screen printing forces ink through the open areas of a stencilled mesh onto the surface below with a squeegee. It lays down the heaviest ink film of any common printing process — typically 0.0004–0.002 in (10–50 µm) dry, against a few microns for pad printing or inkjet — which is why it is the default when a graphic must be fully opaque over a dark or colored substrate, or when the deposited layer has to do a job beyond looking right.
That heavy deposit is also what makes screen printing a functional process, not just a decorative one: conductive silver inks for membrane switches, dielectric layers, resistive elements and solder paste stencils all rely on controlled film thickness. Mesh count governs the trade-off, from around 110 threads per inch for heavy opaque deposits down to 305 and finer for detail work, with minimum line widths of roughly 0.005–0.010 in (0.13–0.25 mm) and registration typically ±0.005–0.010 in (±0.13–0.25 mm). One screen prints one color per pass.
How it works
- Make the screen. Mesh is tensioned on a frame, coated with photosensitive emulsion, exposed through a film positive and washed out. The open areas of the emulsion are where ink will pass. Mesh count, thread diameter and emulsion thickness together determine deposited film thickness.
- Set off-contact. The screen is held a small distance above the substrate. The squeegee presses it into contact only along the line of the stroke, so the mesh snaps back immediately behind the blade. Without off-contact, the screen sticks to the wet ink and smears the image.
- Flood and print. A flood bar fills the open mesh with ink, then the squeegee sweeps across at a controlled angle, pressure and speed, shearing the ink through the mesh onto the substrate. Squeegee durometer, angle and speed are the primary process variables.
- Cure. Solvent inks air dry or pass through a force-dry tunnel at roughly 150–200 °F (65–95 °C). UV inks cure in seconds under a lamp and are standard for high-speed lines. Two-component epoxies are used on glass and metal for adhesion and chemical resistance. Ceramic frit inks on glass are fired at high temperature and become part of the glass, giving a permanent, dishwasher- and abrasion-proof mark.
- Repeat per color. Each additional color is another screen, another pass and another registration operation.
Flat, cylindrical and second-surface
Flat-bed printing handles panels, overlays and nameplates. Cylindrical printing rotates bottles and tubes against a fixed squeegee. Second-surface printing puts the ink on the back of a transparent polycarbonate or polyester overlay so the substrate itself protects the graphic — the standard construction for membrane switches, appliance overlays and instrument panels, where the printed layer never wears because it is never touched.
Design guidelines
Choose mesh count for the job, not for the detail
Low mesh counts around 110 lay down a heavy, opaque, tactile film and are used for solid colors, white over dark, and functional inks. High mesh counts of 305 and above give fine detail and a thin film. You cannot have maximum opacity and finest detail in the same pass — split them across two screens if both are required.
Design to a 0.005–0.010 in minimum line
Lines and gaps below roughly 0.005 in (0.13 mm) will not resolve reliably, and 0.010 in (0.25 mm) is a safer production target. Reversed-out text needs to be larger than positive text at the same weight, because ink spread closes small counters.
Build in registration tolerance
Each color is a separate pass with registration typically ±0.005–0.010 in (±0.13–0.25 mm). Adjacent colors need trapping or a keyline; abutting colors with no overlap will show white gaps or overlaps depending on which way the pass drifts.
Keep the substrate flat or singly curved
The squeegee must maintain contact along a line. Flat and cylindrical surfaces work; compound curves, deep recesses and stepped surfaces do not. Where the surface is complex, pad printing is the appropriate process.
Confirm surface energy and adhesion
As with any ink process, a substrate below roughly 38 dyne/cm — polypropylene, polyethylene, acetal, fluoropolymers — requires flame, corona or plasma treatment before printing. Specify an adhesion test to ASTM D3359 and any chemical, abrasion or UV exposure requirement.
Use second-surface printing when the graphic must not wear
Printing on the reverse of a clear polycarbonate or polyester overlay puts the substrate between the user and the ink. This is why membrane switch legends survive millions of actuations while a first-surface print on the same product would not.
| Feature | Recommended | Limit | Why |
|---|---|---|---|
| Dried ink film | 0.0004–0.002 in (10–50 µm) | — | Far heavier than pad printing or inkjet |
| Mesh count | 110–160 for opacity; 230–305 for detail | — | Mesh controls both film build and resolution |
| Minimum line / gap | 0.010 in (0.25 mm) | 0.005 in (0.13 mm) | Finer detail does not resolve reliably |
| Registration | ±0.005–0.010 in (±0.13–0.25 mm) | Design in trapping | Each color is a separate pass |
| Substrate geometry | Flat or singly curved | Compound curves need pad printing | Squeegee contacts along a line |
| Substrate surface energy | ≥ 38 dyne/cm | Pretreat low-energy plastics | Ink cannot wet the surface otherwise |
Cost drivers
Screen printing has low tooling cost per color and a very low per-piece rate once running, which makes it the economical choice for medium and long runs of flat graphics.
- Color count. One screen, one setup and one pass per color. This dominates both tooling and run cost.
- Screen making and registration setup. Each color needs a film positive, a coated and exposed screen, and registration. Short runs are dominated by this setup.
- Ink system. UV inks cost more per unit but cure instantly and allow much higher line speeds. Two-component and ceramic frit systems carry handling, pot-life and firing costs.
- Substrate preparation. Flame or corona treatment on low-energy plastics is an added in-line operation.
- Part handling. Flat sheets feed fast; three-dimensional parts need nests and often manual loading.
Cost-reduction tactics:
- Reduce color count — a two-color design almost always costs less than half of a four-color one.
- Gang multiple graphics onto one sheet and die cut afterward instead of printing parts individually.
- Use second-surface printing on a clear overlay rather than a first-surface print plus a protective clear coat.
- Standardize on one mesh count and one ink family across a product family so screens and setups are reused.
- For short runs, variable data or photographic imagery, compare against UV inkjet, which has no screens and no per-color setup at all.
Questions
6 questionsHow thick is screen-printed ink?
Typically 0.0004–0.002 in (10–50 µm) dry, far heavier than pad printing or inkjet. That heavy deposit is why screen printing is chosen when a graphic must be fully opaque over a dark substrate, and why it is used for functional layers such as conductive silver inks, dielectrics and solder paste.
What mesh count should I specify?
Around 110–160 threads per inch for heavy, opaque deposits and functional inks; 230–305 and above for fine detail with a thin film. Mesh count sets both film thickness and resolution, so maximum opacity and finest detail cannot be achieved in the same pass — split them across two screens if both are required.
What is the minimum line width for screen printing?
Roughly 0.005 in (0.13 mm) is the resolution limit and 0.010 in (0.25 mm) is a safer production target. Reversed-out text must be larger than positive text at the same weight, because ink spread closes small counters in the characters.
What is second-surface printing?
Printing the graphic on the reverse of a transparent polycarbonate or polyester overlay so the substrate protects the ink. It is the standard construction for membrane switches, appliance overlays and instrument panels, where legends survive millions of actuations because the ink is never touched.
Can screen printing be used on curved parts?
On singly curved surfaces such as bottles and tubes, yes — the part rotates against a fixed squeegee. Compound curves, deep recesses and stepped surfaces do not work because the squeegee needs to maintain contact along a line. Pad printing is the correct process for those geometries.
Screen printing or UV inkjet?
Screen printing for heavy opaque film, functional inks and long runs of the same artwork, where the per-piece rate is very low once the screens are made. UV inkjet for short runs, variable data, photographic images and gradients, since it has no screens and no per-color setup at all.