When it comes to product label printing, precision is key. One crucial aspect that ensures the quality and functionality of your labels is a quality die cut. In this blog, we’ll delve into what die cutting is, what tolerances are, why they matter, and how semi-rotary dies work. We’ll also explain the importance of a safe zone, discuss the common issue of uneven borders, and offer recommendations to avoid these pitfalls.
What Is Die Cutting?
Die cutting is a fabrication process, used in a variety of industries, that uses specialized tools called dies to cut shapes out of various materials, including paper, plastic, fabric, and metal. In product label printing, this process involves cutting labels into specific shapes and sizes from a larger sheet or roll of material. The process ensures that each label is uniform and fits the design specifications. For labels finished on rolls, dies are precisely made so that the tool cuts through the top face stock, but does not puncture the liner underneath. That is micrometers of precision!
There are different types of die cutting used in label printing:
Flatbed Die Cutting:
Uses a flat die and press to cut the material. It is ideal for small runs and thick materials. Flatbed dies are also used for special process applications like hot stamping and embossing. They are also commonly used for what is known as a metal to metal die cut which cuts through the face stock and the liner leaving behind one individual label or sticker with no liner bordering the print.
Rotary Die Cutting:
Uses a cylindrical die on a rotary press to cut materials. It is suitable for high-speed, high-volume runs. In order for labels to use rotary die cutting, the die cylinder must align precisely with the length of the print. IE if a label is 8″ long and there is a 0.125″ gap between each label, the die cylinder must have a circumference that is a multiple of 8.125″.
Semi-Rotary Die Cutting:
A variation of rotary die cutting where the die does not complete a full rotation, but instead uses an eye mark to realign with the print after each partial rotation, more on this below. This option offers flexibility and precision for shorter runs. Die cylinders as mentioned above are more expense to purchase and more time consuming to change out than the flexible metal die itself, it is more cost and time effective to use semi-rotary dies on a fixed die cylinder.
The die cutting process involves:
1. Design: Creating a die that matches the desired label shape.
2. Setup: Installing the die on the die cutting machine. At Columbine Label, most orders are cut with semi rotary using a flexible metal die that is magnetically attached to the die cylinder.
3. Cutting: Feeding the material through the machine to cut out the labels.
4. Inspection: Ensuring each label meets the required specifications.
Die cutting is essential in label printing because it allows for the creation of intricate shapes and designs that enhance the appearance and functionality of labels.
What Are Die Cutting Tolerances?
Die cutting tolerances refer to the acceptable variations in the cut dimensions of a label. These tolerances are necessary because, during the die cutting process, slight shifts can and do occur. These shifts can be due to machine limitations, material properties, or environmental factors. To ensure that the final product meets the desired specifications, printers need to account for these potential variations.
The Importance of a Safe Zone
In label design, the safe zone is an area inside the die line where no important elements (like text or logos) should be placed. At Columbine Label, we require a safe zone of 1/16th of an inch on all sides. This margin ensures that even if there is a slight shift during the die cutting process, critical design elements will not be cut off. Here’s why adhering to the safe zone is essential:
– Prevents Cutting Off Important Elements: Ensuring that no crucial design elements are within the safe zone means that your text, logos, and images remain intact and legible.
– Maintains Design Integrity: By keeping elements away from the edge, you maintain a clean and professional look, even if there are minor variations in the cut.
Other important information about setting up art that is print-ready can be found on our Art Guidelines page.
How Semi-Rotary Dies Work
Semi-rotary die cutting is a popular method used in label printing. It involves a flexible die that rotates partially, cutting the label material in a precise pattern. Here’s a brief overview of how it works:
1. Setup: The flexible die is magnetically mounted onto a cylinder.
2. Rotation: As the material moves through the press, the die rotates partially, making the necessary cuts.
3. Repetition: The machine jogs the material and the die back into alignment using the eye mark printed in the margin of the material. Then the process repeats for each label, ensuring consistency and precision.
This method is preferred for its ability to handle short runs and quick changeovers, making it ideal for custom label production.
The Necessity for Tolerances
Even with advanced technology, there are always slight variations in the die cutting process. Tolerances are essential because they:
– Compensate for Machine Variations: No machine can cut with perfect precision every time. Tolerances account for these small deviations.
– Ensure Consistency: By setting tolerances, you ensure that each label meets the minimum quality standards, even if there are minor discrepancies.
– Avoid Waste: Properly set tolerances help minimize waste by reducing the number of labels that need to be discarded due to imperfections.
Avoiding Uneven Borders
One common issue in label printing is uneven borders. This happens because even slight variations in the cutting process can make a solid border appear uneven. Here’s why we recommend against solid borders at the edge of a label:
– Visibility of Tolerances: Any slight deviation in the cut becomes immediately noticeable with solid borders, making the label look unprofessional.
– Aesthetic Impact: Uneven borders can detract from the overall design, making the label appear poorly made.
Instead, we recommend designing your labels without solid borders at the edges. This approach accommodates the natural variations in the die cutting process, ensuring a cleaner and more professional final product.
Conclusion
Understanding and respecting tolerances is essential for producing high-quality product labels. By maintaining a safe zone, understanding the workings of semi-rotary dies, and avoiding solid borders, you can ensure that your labels look professional and meet your design standards. At Columbine Label, we’re committed to helping you create labels that not only meet your needs but also exceed your expectations. If you have any questions or need assistance with your label design, feel free to reach out to us.