Box Size
Material
Quantity
Essential
23-point automated check
Free
Advanced
41-point inspection by a prepress technician
FREE if using your Print Perk Points at checkout
Order summary:
Custom Mailer Boxes
Quantity: x5 | Box Size: 100 x 100 x 22mm | Material: White Coated E-Flute | Printed Sides: Single Sided | Finishing Types: Cut to Shape |
Artwork Technical Check: Essential - FREE
See what our customers say about Custom Mailer Boxes
Product description
Reinvent shipping experiences with our custom Mailer Boxes, where each delivery becomes an opportunity to impress. Whether handling your Etsy shipping, delivering gifts or sending promotional items, these boxes are built to make a statement from the outside.
Available in three sizes—and made from durable white coated E-flute, our parcel boxes are designed to both look stylish and withstand the journey. Choose single sided printing to personalise your letterbox packaging and ensure your messaging shines the moment it arrives at your customer's doorstep.
Perfect for businesses looking to make an impact with their deliveries, our mailer boxes blend practicality with style, creating a lasting impression long after the box has been opened. Make your personalised postal boxes not just functional but unforgettable.
Etsy deliveries, parcel shipping, promotional giveaways, custom subscription boxes and more.
Top tip
Take your packaging to the next level by printing on the outside of your custom mailer boxes. This creates a seamless, all-around branded experience that surprises and impresses your customers from the moment they open the box.
Looking for more ways to elevate your packaging? Discover our wide range of custom packaging solutions.
Design guidelines
To make artwork setup simple, download the relevant template from the Production templates section above. Follow the instructions provided and remember to remove the 'Guide' layer before exporting your artwork as a PDF.
For the best printing results, ensure your artwork and images are in CMYK. If you use RGB, Pantone or spot colours, these will be converted to CMYK during production, which may affect how your colours appear in print.
To avoid font issues, make sure all fonts are embedded or converted to outlines before exporting your PDF. For readability, we recommend using a minimum font size of 10pt.
For the best print quality, aim for images between 300dpi and 450dpi at their final print size. Lower resolutions may appear blurry or pixelated, while higher resolutions can increase file sizes. Check product template for any specific requirements.
To avoid alignment issues during cutting, include crop marks with a 10mm offset and document bleed when exporting your artwork as a PDF. Refer to the relevant product template for the required bleed specifications, as these vary by product.
All artwork must be supplied as a print ready PDF. We recommend exporting in Adobe PDF (Print) format, ideally using the PDF/X 1a:2001 standard.
Need more help preparing your artwork Explore our support guides for further guidance.
Designing with Canva
We offer free Canva templates for many of our products, complete with the correct dimensions, bleed and safe zones. Where available, you'll find the Canva template in the Production templates section above, ready to open and personalise.
Once your design is complete, download it as a PDF Print file and return to our website to place your order and upload your artwork. Remember to remove any guide layers before exporting.
Need help getting started? Read our Canva template guide or explore our wider collection of Canva templates for other products.
Canva uses RGB colour mode by default, which is designed for screens rather than print. For the best printing results, make sure you select CMYK when exporting your artwork. Converting from RGB to CMYK can cause slight colour shifts, so always check your exported PDF carefully before uploading to avoid unexpected results.
Need help with colours? Read our Canva colour guide.
Use fonts of at least 10pt to maintain legibility and keep important text within the safe zone. Use images at 300dpi or higher at their final size to avoid blurry or pixelated results.
Need help with image quality? Read our artwork resolution guide or watch our YouTube tutorial on how to export Canva designs for print.
Extend backgrounds, colours and images into the bleed area to avoid unwanted white edges after trimming. Keep important text, logos and design elements within the safe zone, and follow the bleed requirements for your chosen product.
Need help setting up bleed? Read our Canva bleed setup guide.
When exporting your finished design from Canva, select PDF Print and enable 'Crop Marks and Bleed'. This ensures your artwork includes the necessary bleed for printing. Remember to remove any template guides before downloading your file.
Need help exporting your artwork? Explore our Canva Hub for further guidance, or watch our tutorial below.
Product description
Reinvent shipping experiences with our custom Mailer Boxes, where each delivery becomes an opportunity to impress. Whether handling your Etsy shipping, delivering gifts or sending promotional items, these boxes are built to make a statement from the outside.
Available in three sizes—and made from durable white coated E-flute, our parcel boxes are designed to both look stylish and withstand the journey. Choose single sided printing to personalise your letterbox packaging and ensure your messaging shines the moment it arrives at your customer's doorstep.
Perfect for businesses looking to make an impact with their deliveries, our mailer boxes blend practicality with style, creating a lasting impression long after the box has been opened. Make your personalised postal boxes not just functional but unforgettable.
Etsy deliveries, parcel shipping, promotional giveaways, custom subscription boxes and more.
Top tip
Take your packaging to the next level by printing on the outside of your custom mailer boxes. This creates a seamless, all-around branded experience that surprises and impresses your customers from the moment they open the box.
Looking for more ways to elevate your packaging? Discover our wide range of custom packaging solutions.
Design guidelines
To make artwork setup simple, download the relevant template from the Production templates section above. Follow the instructions provided and remember to remove the 'Guide' layer before exporting your artwork as a PDF.
For the best printing results, ensure your artwork and images are in CMYK. If you use RGB, Pantone or spot colours, these will be converted to CMYK during production, which may affect how your colours appear in print.
To avoid font issues, make sure all fonts are embedded or converted to outlines before exporting your PDF. For readability, we recommend using a minimum font size of 10pt.
For the best print quality, aim for images between 300dpi and 450dpi at their final print size. Lower resolutions may appear blurry or pixelated, while higher resolutions can increase file sizes. Check product template for any specific requirements.
To avoid alignment issues during cutting, include crop marks with a 10mm offset and document bleed when exporting your artwork as a PDF. Refer to the relevant product template for the required bleed specifications, as these vary by product.
All artwork must be supplied as a print ready PDF. We recommend exporting in Adobe PDF (Print) format, ideally using the PDF/X 1a:2001 standard.
Need more help preparing your artwork Explore our support guides for further guidance.
Designing with Canva
We offer free Canva templates for many of our products, complete with the correct dimensions, bleed and safe zones. Where available, you'll find the Canva template in the Production templates section above, ready to open and personalise.
Once your design is complete, download it as a PDF Print file and return to our website to place your order and upload your artwork. Remember to remove any guide layers before exporting.
Need help getting started? Read our Canva template guide or explore our wider collection of Canva templates for other products.
Canva uses RGB colour mode by default, which is designed for screens rather than print. For the best printing results, make sure you select CMYK when exporting your artwork. Converting from RGB to CMYK can cause slight colour shifts, so always check your exported PDF carefully before uploading to avoid unexpected results.
Need help with colours? Read our Canva colour guide.
Use fonts of at least 10pt to maintain legibility and keep important text within the safe zone. Use images at 300dpi or higher at their final size to avoid blurry or pixelated results.
Need help with image quality? Read our artwork resolution guide or watch our YouTube tutorial on how to export Canva designs for print.
Extend backgrounds, colours and images into the bleed area to avoid unwanted white edges after trimming. Keep important text, logos and design elements within the safe zone, and follow the bleed requirements for your chosen product.
Need help setting up bleed? Read our Canva bleed setup guide.
When exporting your finished design from Canva, select PDF Print and enable 'Crop Marks and Bleed'. This ensures your artwork includes the necessary bleed for printing. Remember to remove any template guides before downloading your file.
Need help exporting your artwork? Explore our Canva Hub for further guidance, or watch our tutorial below.





Custom mailer boxes are sturdy, packaging solutions made from corrugated cardboard, tailored to fit specific branding needs. They feature a self-locking mechanism for easy assembly and come in various sizes. These boxes are perfect for shipping merchandise and gifts, providing protection during transit to ensure they arrive in excellent condition.
100 x 100 x 22mm: This small postal box meets Royal Mail's large letter size requirements, perfect for compact items.
255 x 168 x 22mm: This medium postal box meets Royal Mail's large letter size requirements, suitable for medium sized items.
600 x 182 x 35mm: This large postal box meetings Royal Mail's medium parcel size requirements, well-suited for larger items.
All of the aforementioned sizes are designed to comply with Royal Mail size requirements; however it is important to remember that letterbox sizes can vary on individual doors, so be sure to keep this in mind when choosing a specific size.
E-flute: This lightweight reinforced board features a smooth, bright white surface, making it an ideal choice for printed postal boxes.
Custom postal boxes are supplied flat for easy self-assembly. To assemble, begin by folding along the pre-scored lines on the cardboard. Next, insert the interlocking tabs into their corresponding slots to secure the box’s structure. Once the tabs are locked in place, fold the top and bottom flaps over and tuck them in to close the box. Make sure all edges are aligned properly and the box is securely sealed before use.
Yes, our postal boxes are recyclable since they are constructed from corrugated cardboard. To recycle them properly, remove any contents, clean off any residue, and flatten the box. Always check local recycling guidelines, as practices may vary by region.
Turnaround times depend on your chosen product specifications and finishing options. For faster delivery, we offer express production upgrades at an additional cost. (Quantity limits apply) To avoid delays, make sure we receive your artwork before the cut off time shown on the product page and in your basket.
Please note: If your artwork is uploaded after the cut off time, or corrected artwork isn't supplied before the next cut off following rejection, delivery will be delayed by one working day.
Standard UK delivery is free, with optional paid upgrades for faster delivery, including before 10.30am and 12 noon services where available.
Yes, we offer international delivery. Contact our Bespoke team for a shipping quote.
Yes, we can arrange split deliveries to multiple addresses. Contact our Bespoke team with your requirements, and we'll help arrange delivery.
Once you've placed your order, you can upload your print ready PDF artwork using the upload button on the confirmation page. Alternatively, upload your files through the Orders section of My Account.
Need a hand? Watch our step by step video guide to see how to upload your artwork.
Colour matching isn't available on standard online orders. If you need to match a specific colour, submit a bespoke quote request and our team will review your requirements.
Most orders are packaged in boxes, while larger quantities may be secured on a pallet for kerbside delivery. If your location has access restrictions or requires special delivery arrangements, please contact us after placing your order, with your order number to hand.
Custom mailer boxes are sturdy, packaging solutions made from corrugated cardboard, tailored to fit specific branding needs. They feature a self-locking mechanism for easy assembly and come in various sizes. These boxes are perfect for shipping merchandise and gifts, providing protection during transit to ensure they arrive in excellent condition.
100 x 100 x 22mm: This small postal box meets Royal Mail's large letter size requirements, perfect for compact items.
255 x 168 x 22mm: This medium postal box meets Royal Mail's large letter size requirements, suitable for medium sized items.
600 x 182 x 35mm: This large postal box meetings Royal Mail's medium parcel size requirements, well-suited for larger items.
All of the aforementioned sizes are designed to comply with Royal Mail size requirements; however it is important to remember that letterbox sizes can vary on individual doors, so be sure to keep this in mind when choosing a specific size.
E-flute: This lightweight reinforced board features a smooth, bright white surface, making it an ideal choice for printed postal boxes.
Custom postal boxes are supplied flat for easy self-assembly. To assemble, begin by folding along the pre-scored lines on the cardboard. Next, insert the interlocking tabs into their corresponding slots to secure the box’s structure. Once the tabs are locked in place, fold the top and bottom flaps over and tuck them in to close the box. Make sure all edges are aligned properly and the box is securely sealed before use.
Yes, our postal boxes are recyclable since they are constructed from corrugated cardboard. To recycle them properly, remove any contents, clean off any residue, and flatten the box. Always check local recycling guidelines, as practices may vary by region.
Turnaround times depend on your chosen product specifications and finishing options. For faster delivery, we offer express production upgrades at an additional cost. (Quantity limits apply) To avoid delays, make sure we receive your artwork before the cut off time shown on the product page and in your basket.
Please note: If your artwork is uploaded after the cut off time, or corrected artwork isn't supplied before the next cut off following rejection, delivery will be delayed by one working day.
Standard UK delivery is free, with optional paid upgrades for faster delivery, including before 10.30am and 12 noon services where available.
Yes, we offer international delivery. Contact our Bespoke team for a shipping quote.
Yes, we can arrange split deliveries to multiple addresses. Contact our Bespoke team with your requirements, and we'll help arrange delivery.
Once you've placed your order, you can upload your print ready PDF artwork using the upload button on the confirmation page. Alternatively, upload your files through the Orders section of My Account.
Need a hand? Watch our step by step video guide to see how to upload your artwork.
Colour matching isn't available on standard online orders. If you need to match a specific colour, submit a bespoke quote request and our team will review your requirements.
Most orders are packaged in boxes, while larger quantities may be secured on a pallet for kerbside delivery. If your location has access restrictions or requires special delivery arrangements, please contact us after placing your order, with your order number to hand.