How to judge the quality of printing?

I often get asked, “How do I know if my prints are good?” Maybe you’ve seen colors fade after a few washes, edges blur, or entire sections peel off. Understanding these issues helps you maintain consistent, professional outcomes. Let’s break down the critical indicators—color fastness¹, bleeding², ink breakage, peeling, and registration—and learn how to avoid them.

Each print defect—whether it’s fading color, fuzzy edges, broken lines, or poor alignment—signals specific root causes. You’ll see why some fabrics exhibit color shifts after laundering, why edges bleed when the paste is too thin, and why prints peel if curing is insufficient. By mastering these checks, you can ensure vibrant, durable prints on every piece.

Let’s dive in so you can avoid these pitfalls.

What will happen if the color fastness fails? Detailed explanation of the judgment criteria and test methods

Poor color fastness leads to prints fading after washing, rubbing, or sun exposure. This diminishes the garment’s aesthetic and can damage brand reputation. Let’s see how color fastness is measured.

Color fastness indicates how well the dye or ink adheres to fibers. Low fastness means prints can bleed, fade, or transfer onto other clothes. Common tests replicate real-world conditions—laundry, friction, or direct sunlight. Brands typically set minimum levels for each category to ensure customer satisfaction.

Color Shift Tees

What is color fastness? How many common levels are there?

Color fastness is a measure of the print’s ability to retain color under various stresses. Standards often use a scale of 1 to 5, where 5 is excellent (least color change) and 1 is poor (significant change). Different tests target different exposures—wash, rub, perspiration, light, etc.

How to evaluate the color fastness of printing by washing, rubbing, sun exposure, etc.?

• Wash fastness: Simulates home or industrial laundry. Prints are assessed for color change and staining of adjacent fabrics.
• Rub fastness: A crock meter drags a white cloth over the print, checking how much color transfers.
• Light fastness: Exposing samples to a standardized light source for set durations.

Consistency is key. If repeated tests yield the same rating, you can trust those results.

Bleeding problem: Technical causes and control measures for blurred and diffused edges of printing

Bleeding describes when ink or dye spreads beyond the intended border, causing fuzzy outlines. Let’s see why that happens.

Bleed is often due to over-saturated inks, watery paste, or improper substrate pretreatment. On some fabrics, capillary action draws the ink sideways. Controlling ink viscosity, squeegee pressure, and drying steps helps keep crisp lines.

Why does the edge of the pattern bleed? Is it a fabric problem or a process problem?

It can stem from both. Fabrics with loose weaves or high absorbency can let ink spread unpredictably. Overly thin or runny ink magnifies that effect. Too much pressure or slow drying also encourages wicking. Solutions range from refining the ink mix to adjusting how quickly the print cures.

How to adjust the concentration of printing paste and scraping pressure to prevent bleeding?

• Concentration: Thicken the paste if edges are consistently fuzzy. This reduces flow and speeds surface drying.
• Scraping pressure: Lighter passes may deposit less ink, lowering bleed risk. Conversely, too little pressure may under-deposit.
• Immediate flash cure: In screen printing, flash curing quickly between colors sets the design before it can bleed.

Ink breakage phenomenon: What should I do if the pattern is interrupted and the line is missing, affecting the visual effect?

Ink breakage means interrupted lines or missing segments in a design. It might look like a dashed line when it should be continuous.

Breakage is common in digital printing if nozzles clog, or if the artwork has single-pixel lines the printer can’t reproduce. Screen printing can also skip if the screen isn’t coated or squeegeed well. Each method calls for its own maintenance and calibration protocols to ensure complete coverage.

Why is it easy for digital printing to break ink? Is it a nozzle blockage or a problem with the artwork?

• Nozzle blockage: Dried ink or dust can partially obstruct jets. Regular head cleaning or humidity control solves this.
• File resolution or color mapping: Very thin lines may not print cleanly if the resolution is too low.
• Ink supply: If the printer runs low on ink or experiences flow disruptions, lines skip mid-print.

Does screen printing also break ink? How to prevent it?

Screen printers can skip if:

1. Mesh tension is uneven.
2. Emulsion thickness is inconsistent, leading to partial ink transfer.
3. Squeegee angle or speed is off, leaving voids.

Prevent by ensuring consistent screen prep, proper squeegee technique, and stable ink viscosity.

Printing peeling/powdering: Analysis of the root causes of surface shedding and cracking

Peeling or powdering is when the printed layer comes off in flakes or cracks. This ruins aesthetics and longevity. Let’s see why it happens.

Thick or poorly bonded layers can peel, especially on stretchy or laundered garments. Glue-based or special effects prints (flocking, foaming) rely on correct adhesives and thorough curing to lock them in place. Even slight deviations in heat or time can sabotage adhesion and lead to cracks.

Why are glue, flocking, and foaming printing prone to peeling?

They add extra layers on top of fabric rather than embedding color into fibers. If adhesives or resins don’t fully bond (due to inadequate pressure, time, or temperature), the design may separate from the garment. Additionally, heavy mechanical stress (stretching, abrasion) tests these raised or layered prints.

Is it related to the color fixing and drying process? How to optimize the process?

Post-print fixation often uses heat or chemical treatments:

1. Proper temperature/time ensures adhesives cure thoroughly.
2. Correct pressure might be needed in certain processes (like heat-press).
3. Ventilation: Ensure moisture or solvents evaporate uniformly.

Running test washes or stress tests helps confirm the design’s durability.

Does the printing position deviation affect the quality of the finished garment? The registration problem cannot be ignored!

A design that’s off-center or incorrectly aligned undermines the garment’s visual appeal. Let’s see how to handle it.

Position deviation might seem minor, but especially in multi-color or pattern repeats, alignment errors scream low quality. Mass production amplifies small mistakes. Overprint registration ensures layers line up consistently, crucial for brand logos or complex graphics.

Why is it easy to have inaccurate position in mass production?

• Human error: Operators repeatedly positioning garments by hand can drift over long runs.
• Machine calibration: Pallet misalignment or screen shifting accumulates small deviations.
• Fabric shrinkage: If the fabric dimension changes between prints or after a flash cure, alignment falters.

How to improve accuracy through overprint positioning and automatic registration equipment?

• Registration marks: Simple crosshairs or targets help align each screen or color.
• Pallet consistency: Regularly check for loosened clamps or warped pallets.
• Auto-registration systems: Some advanced presses read alignment marks and adjust in real time, boosting precision.

Conclusion

Assessing print quality means checking for color fastness, crisp edges, continuous lines, solid adhesion, and accurate placement. Each defect—fading, bleeding², breakage, peeling, or misalignment—stems from specific root causes. By refining ink chemistry, controlling printing parameters, and implementing tight QA checks, you can deliver garments that look great, wear well, and impress customers with reliable consistency.