Envelopes

Find the answers you need below. If you have any additional questions, our customer service team is always here to support you.

Question 1: Which envelopes are best for professional business correspondence?
For professional business correspondence, window envelopes in DIN long (DL) or C5 format are the most popular choice. Window envelopes allow the recipient's address to show through directly from the letter, saving time and reducing errors. Self-seal envelopes are ideal for high-volume mailings as they eliminate the need for moistening. White business envelopes convey professionalism and are suitable for invoices, contracts, and official communications. At karton.eu, you'll find all standard formats available from stock with fast delivery throughout Europe, and we offer attractive bulk discounts for businesses and government agencies ordering in larger quantities.

Question 2: What is a DL envelope and what is it used for?
DL envelopes (also called DIN long envelopes) measure 110 x 220 mm and are the most common envelope format for business mail in Europe. The 'DL' designation stands for 'dimension lengthwise' and is designed to hold A4 paper folded into thirds. DL envelopes are perfect for standard business letters, invoices, statements, and official correspondence. They are available with or without windows, and with various closure types including self-seal and gummed. Our DL envelopes are available from stock at competitive prices with same-day dispatch for orders placed early, ensuring your business correspondence is never delayed.

Question 3: What is the difference between self-seal and gummed envelopes?
Self-seal envelopes (also called peel-and-seal or self-adhesive envelopes) feature a protective strip that you simply peel off to expose the adhesive, then press to seal—no moisture needed. This makes them ideal for high-volume mailings and faster processing. Gummed envelopes require moistening the adhesive strip before sealing, which is the traditional method. Self-seal envelopes offer several advantages:

• Faster and more hygienic sealing process
• Stronger, more secure adhesive bond
• Better for automated mailing systems

While self-seal envelopes have a slightly higher price point, they save time in busy office environments. Both types are available at karton.eu with reliable European-wide delivery.

Question 4: What are the differences between C4, C5, and C6 envelope formats?
The C-series envelope formats correspond to standard paper sizes: C4 envelopes (229 x 324 mm) hold unfolded A4 documents and are ideal for sending certificates, contracts, or brochures flat. C5 envelopes (162 x 229 mm) accommodate A4 paper folded once and are popular for greeting cards, invitations, and larger mailings. C6 envelopes (114 x 162 mm) fit A4 folded twice or A6 cards and are commonly used for postcards and personal correspondence. Each format is available in various qualities including window and plain versions, self-seal or gummed closures, and both white and brown options. At karton.eu, all DIN formats are competitively priced and shipped quickly from our extensive stock.

Question 5: How do window envelopes work and where should the address be positioned?
Window envelopes feature a transparent panel (usually made of glassine or film) that displays the recipient's address printed on the document inside, eliminating the need to write or print addresses separately. For standard DL window envelopes, the address should be positioned 45-50 mm from the top edge and 20 mm from the left edge of an A4 sheet folded into thirds. This ensures proper visibility through the window. The window is typically located on the lower right section of the envelope face. Window mailing envelopes are particularly efficient for invoices, statements, and form letters where addresses are already printed. Our window envelopes meet all postal standards and are available with same-day dispatch when ordered from karton.eu.

Question 6: Do you offer bulk discounts when ordering envelopes in large quantities?
Yes, we offer attractive bulk discounts for envelopes ordered in wholesale quantities. Businesses, government agencies, and organizations can benefit from our tiered pricing structure—the more you order, the lower the unit price. Whether you need business envelopes for daily office operations or large quantities for seasonal mailings, our flexible ordering system accommodates both small and large volumes. We accept payment via invoice for established business customers, making procurement simple and efficient. All bulk orders are shipped quickly from stock with reliable European-wide delivery, and customers in mainland Germany enjoy complimentary standard shipping. Contact our team for personalized quotes on large-volume envelope orders and take advantage of our competitive wholesale prices.

Question 7: Are envelopes available in different colors besides white?
Yes, while white envelopes are the most common choice for professional business correspondence, we also stock brown envelopes (also called manila or kraft envelopes) which are popular for internal mail, archiving, and cost-effective bulk mailings. Brown envelopes offer a more economical option while still maintaining durability and functionality. Some formats are also available in additional colors for special occasions or branding purposes. White business envelopes convey the highest level of professionalism and are preferred for external corporate communications, invoices, and official documents. Our entire envelope range is available from stock at competitive prices with fast delivery. Whether you need classic white envelopes or practical brown alternatives, karton.eu has supplied reliable envelope solutions since 2007.