---
product_id: 60377604
title: "Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50"
brand: "blake"
price: "$315.53"
currency: USD
in_stock: true
reviews_count: 13
category: "Blake"
url: https://www.desertcart.ec/products/60377604-blake-purely-packaging-c3-a3-450-x-324-mm-board
store_origin: EC
region: Ecuador
---

# 450 x 324 mm C3 size Strong peel & seal closure Heavy-duty board back protection Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50

**Brand:** blake
**Price:** $315.53
**Availability:** ✅ In Stock

## Summary

> 📬 Protect your mail like a pro — because your important documents deserve the best!

## Quick Answers

- **What is this?** Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50 by blake
- **How much does it cost?** $315.53 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ec](https://www.desertcart.ec/products/60377604-blake-purely-packaging-c3-a3-450-x-324-mm-board)

## Best For

- blake enthusiasts

## Why This Product

- Trusted blake brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Bulk Pack Efficiency:** 50 envelopes per pack, perfect for busy offices aiming to streamline secure mailings.
- • **Premium Manilla Finish:** Professional, lightweight manilla color enhances brand image and mail presentation.
- • **Effortless Security Seal:** Peel & seal closure ensures quick, tamper-evident mailing with lasting freshness.
- • **Clear 'Do Not Bend' Warning:** Printed front message reduces risk of mishandling during transit.
- • **Ultimate Flat Mail Protection:** Rigid board backing shields certificates, prints, and photos from bending or damage.

## Overview

Blake Purely Packaging C3 Board Back Envelopes (450 x 324 mm) combine heavy-duty cardboard backing with a strong peel & seal closure, offering superior protection for certificates, photographs, and prints. Featuring a clear 'Please do not bend' print, these manilla envelopes come in a convenient pack of 50, ideal for professional mailings that demand durability and security.

## Description

From the manufacturer Choose from a wide selection of packaging solutions to offer your mailings maximum protection and a secure delivery. Our range includes standard, everyday use products such as: Cushioned Padded Envelopes, One-Touch Cardboard Boxes, Postal Tubes and Book Wraps. Along with more unusual, creative solutions such as our Metallic Bubble Envelopes, Cash Transit Bags and Polythene mailing security bags. At Blake there’s so much more to packaging than just plain brown cardboard boxes. Our packaging range has over 32 colours to choose from which promote your brand, protect your contents and maximise ROI.

Review: The only brand of board backed envelopes I will buy - Excellent board backed envelopes, with 'please do not bend' printed clearly on them. I made the mistake recently of buying a cheaper alternative and definitely regret it. (For the saving of several pounds, I am now stuck with more than 100 flimsy, bendable envelopes with an unpleasant font on the front!) Both the grey board and the brown kraft paper used are of decent thickness to protect most flat items. They are also durable and reliable. Would definitely recommend. Although, for e.g. single prints, they might still need cardboard stiffeners so bear this in mind.
Review: Great product - Very durable, functions well. Seals very well. Postage is protected. Great value for money. Brought many times. Light brown colour. Can be used for cards and large letter. Lightweight

## Features

- Make a difference to your mail with these Purely Packaging Board Back envelopes by Blake
- Heavy Duty Board Back to protect certificates, photographs, prints and more
- Strong Peel & Seal closure for ease of use, additional security and longer shelf life
- Printed 'Please do not bend' on the face for extra safety
- Printed Do Not Bend on the front

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00O4X7W00 |
| Best Sellers Rank | 15,111 in Stationery & Office Supplies ( See Top 100 in Stationery & Office Supplies ) 180 in Envelopes |
| Brand | Blake |
| Brand Name | Blake |
| Closure Type | Self-Seal |
| Closure type | Self-Seal |
| Colour | Manilla |
| Customer Reviews | 4.6 out of 5 stars 2,299 Reviews |
| Global Trade Identification Number | 05055559719472, 05055559753087 |
| Item Dimensions L x W | 45L x 32.4W centimetres |
| Item Shape | Rectangular |
| Item Type Name | Purely Packaging C3 450x324mm Board Back Envelope Box of 50 |
| Item Weight | 2.49 kg |
| Manufacturer | Blake Envelopes |
| Material | Cardboard, Cardstock, Paper |
| Material Type | Cardboard, Cardstock, Paper |
| Model Name | Everyday - Board Back Envelopes |
| Number of Items | 50 |
| Number of items | 50 |
| Occasion | Envelopes |
| Occasion Type | Arts and Craft, Business, Envelopes, Mailing, Office |
| Recommended Uses For Product | Business, Envelopes, Invitation Card, Letter, Office |
| Size | C3 450 x 324 mm |
| Special Features | Board, Card, Lightweight, Premium, Self-Adhesive Closure |
| Style | Pack of 50 (No Window) |
| Unit Count | 50.0 count |

## Product Details

- **Brand:** Blake
- **Closure type:** Self-Seal
- **Colour:** Manilla
- **Material:** Cardboard, Cardstock, Paper
- **Occasion:** Envelopes

## Images

![Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50 - Image 1](https://m.media-amazon.com/images/I/81S2chsbi1L.jpg)
![Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50 - Image 2](https://m.media-amazon.com/images/I/51tbdcM9eDL.jpg)
![Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50 - Image 3](https://m.media-amazon.com/images/I/91pcEkCy2CL.jpg)
![Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50 - Image 4](https://m.media-amazon.com/images/I/71kt-dr7YoL.jpg)
![Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50 - Image 5](https://m.media-amazon.com/images/I/61bgTwDlhuL.jpg)

## Available Options

This product comes in different **Color, Size, Style** options.

## Questions & Answers

**Q: which size is a4? c4?**
A: The 'A' prefix is the paper size; the 'C' prefix is the envelope size. A4 paper fits unfolded inside a C4 envelope (similarly A5/C5, A6/C6, etc).

**Q: What is the gsm of both the paper and the board? Want a thick board back that won’t easily bend**
A: I don't know what the gsm is but I found them pretty sturdy and sent photos using them.

**Q: would my card 160cm x 155cm fit in this envelope**
A: Yes the envelopes are 229 x 162 so your items would fit.

**Q: Will this fit a A3 print?**
A: Yes.  I use it to fit A3 booklets.

## Customer Reviews

### ⭐⭐⭐⭐⭐ The only brand of board backed envelopes I will buy
*by T***R on 6 December 2024*

Excellent board backed envelopes, with 'please do not bend' printed clearly on them. I made the mistake recently of buying a cheaper alternative and definitely regret it. (For the saving of several pounds, I am now stuck with more than 100 flimsy, bendable envelopes with an unpleasant font on the front!) Both the grey board and the brown kraft paper used are of decent thickness to protect most flat items. They are also durable and reliable. Would definitely recommend. Although, for e.g. single prints, they might still need cardboard stiffeners so bear this in mind.

### ⭐⭐⭐⭐⭐ Great product
*by V***. on 30 December 2024*

Very durable, functions well. Seals very well. Postage is protected. Great value for money. Brought many times. Light brown colour. Can be used for cards and large letter. Lightweight

### ⭐⭐⭐⭐⭐ Excellent value
*by F***R on 31 August 2019*

These are slightly flimsier than I’ve bought in the past and the ‘Do not bend’ is pink rather than red. But this is more than reflected in the price and that makes them excellent value for money. I use them to send A4 presentation folders holding up to 12 sheets of quality paper and everything fits in perfectly.

## Frequently Bought Together

- Blake Purely Packaging C3 (A3) 450 x 324 mm Board Back Pocket Peel & Seal Envelopes (4200/50) Manilla - Pack of 50
- A3 Cello Bags - Crystal Clear & Good Thickness - for A3 Artwork/Photos (420MM x 306MM) - Makes Your Work Feel Pricey - 30mm Seal - 40Micron - Super Strong Seams
- House of Card & Paper Grey Kraft Board 1500micron 945gsm A3 Size 30 Sheets per Pack, HCP476

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*Product available on Desertcart Ecuador*
*Store origin: EC*
*Last updated: 2026-07-04*