Why did my sublimation mug turn yellow?

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mecolour

On 2025-01-14

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If your sublimation mug has turned yellow after printing, there could be several reasons for this discoloration. Yellowing typically occurs due to improper conditions during the sublimation process, and it’s important to pinpoint the cause to avoid it in future prints. Understanding these factors is essential for maintaining the quality of your sublimation mugs and ensuring they last long without discoloration.

What causes the sublimation mug to turn yellow?

Sublimation mug turning yellow can occur due to various reasons, many of which are related to the heat press process, the materials used, and the way the mugs are cared for. Let’s break down the primary causes:

1. Overheating During the Sublimation Process
One of the most common causes of yellowing is excessive heat. Sublimation is a delicate process that requires precise temperature control. If the temperature during the transfer process is too high, it can result in the degradation of the coating on the mug. This degradation leads to the yellowing of the surface, which is especially noticeable on white or light-colored mugs.

2. Poor-Quality Mugs or Coatings
Not all sublimation mugs are created equal. Mugs that have a low-quality coating are more prone to yellowing after sublimation. Low-quality ceramic mugs may have subpar coatings that don’t bond well with the sublimation ink. Over time, the coating can break down, leading to discoloration.

3. Incorrect Heat Press Time
The duration of the heat press time can also impact the final appearance of your sublimation mug. Too much exposure to heat can cause the coating to yellow, while insufficient time can result in incomplete sublimation, leaving the design faded or streaky.

4. Exposure to UV Light and Sunlight
Prolonged exposure to sunlight or ultraviolet (UV) light can cause the sublimation ink to degrade over time, which can lead to yellowing. The UV rays can break down the chemical bonds in the sublimation dye, causing it to lose vibrancy and turn yellow.

5. Cleaning and Care Mistakes
Improper cleaning methods can accelerate the yellowing process. Harsh cleaning agents or abrasives can damage the coating on the mug, causing it to become discolored. It’s important to clean your sublimation mugs with care, using mild detergents and soft cloths. Avoid putting them in dishwashers if the manufacturer advises against it, as the high temperatures and chemicals in the dishwasher can cause the mug to lose its brightness and turn yellow.

Cleaning and Care mugs

How to prevent sublimation mugs from turning yellow

Now that we understand the primary causes of yellowing, let’s explore how to prevent it. By following these tips, you can ensure that your sublimation mugs remain vibrant and free of yellow stains for a long time.

1. Use the Correct Temperature and Time Settings
As mentioned earlier, overheating is a significant contributor to yellowing. Always check the temperature settings of your heat press and ensure it is within the recommended range (usually between 380°F to 400°F or 193°C to 204°C). Follow the manufacturer’s guidelines for the time and temperature settings, and if you’re unsure, conduct a small test before committing to a larger batch. The heat press time usually ranges from 45 to 60 seconds.

2. Choose High-Quality Sublimation Mugs
To avoid yellowing due to poor-quality coatings, invest in high-quality sublimation mugs from reputable suppliers. Look for mugs specifically designed for sublimation with premium ceramic coatings that are made to withstand high temperatures. Coated ceramic mugs from well-known brands will not only give you better results but will also last longer without discoloration.

3. Use the Correct Pressure in the Heat Press
In addition to temperature and time, pressure plays a crucial role in achieving a successful sublimation transfer. Too much pressure can cause the coating to break down, while too little pressure can result in an incomplete transfer. Follow the manufacturer’s instructions for pressure settings, and make sure your mug is properly aligned in the heat press to avoid uneven pressure.

Use the Correct Temperature and Time Settings

4. Avoid Prolonged Sun Exposure
To preserve the quality of your sublimation mug, try to avoid exposing it to direct sunlight for extended periods. If you’re displaying your sublimation mugs, keep them in areas where they are not in constant contact with sunlight or UV light. If you plan to sell these mugs, it may be wise to advise your customers to treat them the same way to ensure long-lasting results.

5. Proper Cleaning and Maintenance
Proper cleaning is essential to maintain the appearance of your sublimation mugs. Always clean your mugs gently with mild soap and warm water. Avoid using abrasive sponges or rough cloths, as they can scratch the surface and cause the coating to deteriorate, resulting in yellowing. If the mugs are labeled as hand wash only, make sure to follow this instruction to preserve their quality.

If the mug has already turned yellow, try cleaning it with a non-abrasive cleaning paste specifically designed for ceramic items, but be cautious not to use anything too harsh that could damage the coating further.

Additional Tips for Long-Lasting Sublimation Mugs

1. Store Your Mugs Properly
When storing sublimation mugs, keep them in a cool, dry place away from heat sources. Excessive heat can affect the integrity of the sublimation coating and cause yellowing over time. Avoid stacking mugs on top of each other unless they are properly cushioned to prevent any scratches or damage to the surface.

2. Avoid Harsh Chemicals
Certain chemicals, such as bleach or strong solvents, can strip the coating from your sublimation mugs and cause yellowing. Stick to gentle cleaning products that are safe for ceramics and avoid using strong chemical agents.

3. Use Sublimation-Specific Coatings
Some manufacturers offer specialized coatings that can provide better protection against yellowing. If you’re in the business of creating sublimation mugs, consider using premium coatings or looking for suppliers who offer mugs specifically treated for longevity and better color retention.

Sublimation mug turning yellow can be a frustrating issue, but with the right techniques and proper care, you can prevent it from happening. Always be mindful of the heat press settings, invest in high-quality mugs, and ensure the proper cleaning and storage of your mugs to maintain their appearance. By following these steps, you’ll not only avoid yellowing but also extend the life of your sublimation mugs, ensuring they continue to look vibrant and professional for years to come.