Greeting Cards Packaging: Cello Bags, Envelopes and Postage

Greeting cards packaging needs two things: a clear bag that keeps the card and its envelope clean, and a stiff outer that keeps them flat in the post. For most card and art print sellers that means a cello bag (the trade name is OPP) around each card, then a board back envelope for single orders or a 20mm deep large letter box for small bundles.

This guide covers which of our clear bags suits each common card size, where our range stops (we do not stock small snug card sleeves), which board back envelope takes which card, when a large letter box is the better outer, and how to pack wholesale orders for shops. It ends with how much to buy and what each piece costs per card.

Quick picks for greeting card and print sellers

These three cover a single card order, a small bundle and most art prints.

Best for keeping cards and prints clean

Transparent OPP Bags (Polypropylene)

Clear, glossy polypropylene bags, the kind most shops call cello or cellophane bags.

• 10 sizes, 6.5 x 9 inches (165 x 230mm) to 18 x 22 inches (458 x 560mm)
• Packs of 100
• From £2.50 ex VAT (£3.00 inc VAT)

From £2.50 ex VAT (£3.00 inc VAT)

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Best for posting single cards and prints flat

Board Back Envelopes (Do Not Bend)

Envelopes with a stiff board back and a printed Do Not Bend warning.

• C4 (324 x 229mm), C5 (229 x 162mm) and C6 (162 x 114mm)
• C4 and C5 in boxes of 125, C6 in boxes of 250
• From £12.00 ex VAT (£14.40 inc VAT)

From £12.00 ex VAT (£14.40 inc VAT)

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Best for card bundles under 20mm

Royal Mail PIP Large Letter Boxes

Die cut cardboard boxes 20mm deep, made for the Royal Mail Large Letter rate.

• Mini, C6, DL, C5 and C4 sizes
• Packs of 50, supplied flat
• From £5.00 ex VAT (£6.00 inc VAT)

From £5.00 ex VAT (£6.00 inc VAT)

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What greeting cards packaging do you actually need?

You need a clear bag for presentation and a rigid outer for the post, and for most sellers that is the whole list. The bag keeps fingerprints, dust and damp off the card and holds the card and its envelope together as one unit. The outer stops the corners getting knocked and the card getting folded through a letterbox.

What you pick depends on how the card leaves you. A card sold at a market stall or to a shop only needs the bag. A card posted to a customer needs the outer as well, and the bag becomes optional. Plenty of sellers post a single card with no bag at all, straight into a board back envelope, and that is fine if the card is going to the person who will write in it. Keep the bag for cards that will be displayed, resold or given as bought.

We sell the plain stock for each row: transparent OPP bags, board back envelopes, Royal Mail PIP large letter boxes and kraft paper rolls. We do not sell the cards' own paper envelopes, printed backing cards or custom printed packaging, so those come from your printer or stationery supplier.

Which cello bags for cards fit each card size?

Our smallest cello bag is 6.5 x 9 inches (165 x 230mm), which takes a 5 x 7 inch card or an A5 card with room to spare and is larger than a snug sleeve on A6 and small square cards. Our range stops there: we do not stock small self-seal card sleeves cut a few millimetres bigger than an A6 or 5 x 5 inch card. If a tight sleeve on a small card matters to you, buy that sleeve from a card sleeve specialist and come to us for the bigger bags and the postal packaging.

A bag that is bigger than the card still works. The spare length folds over the back and is held with a sticker, which is how many market sellers bag their cards anyway. The table below matches common card and print sizes to our bag sizes. Card sizes are the standard paper sizes. Check your own card and envelope with a ruler before you order, because printers trim to slightly different finished sizes and envelopes add a few millimetres all round.

All ten sizes come in packs of 100, from £2.50 ex VAT (£3.00 inc VAT) a pack. The bags are clear and glossy, so the card design shows through the front and the envelope sits behind it.

Shop transparent OPP bags

If you are weighing these against softer polythene bags, OPP is the clearer and crisper of the two, which is why card sellers use it. The trade-offs are in our OPP bags vs clear polythene bags comparison.

How do you pack cards in cellophane bags that are bigger than the card?

Put the card and envelope in together, push them to the bottom of the bag, fold the spare over the back and fix it with one sticker. Done neatly, cellophane bags for cards that are a size up look tidy from the front, which is the side a buyer sees on a stall or in a product photo.

1. Stack the card on its envelope. Card face up at the front, envelope behind with the flap side against the back of the card so the flap cannot catch.
2. Slide the pair into the bag. Hold the bag open with one hand and feed the bottom edge of the card in first. Push it right down to the closed end.
3. Square it up. Tap the closed end on the bench so the card sits level, then smooth the bag flat from the bottom up to push the air out.
4. Fold the spare over the back. Crease the bag along the top edge of the card and fold the spare length down behind it. On a narrow card, fold the spare width behind as well.
5. Fix it. One small sticker or a short strip of clear tape across the fold holds it shut. A sticker with your shop name on it closes the bag and labels it in one go.
6. Check the front. Turn it over. The front should be one smooth layer with no fold lines across the design.

For multi packs, the spare room is useful. A set of several A6 cards with envelopes makes a thicker stack that fills the 6.5 x 9 inch (165 x 230mm) bag better than one card does. Stack cards at the front and envelopes at the back, so the top design shows.

For art prints, add a sheet of stiff card behind the print inside the bag. We do not sell backing boards, but greyboard or offcuts of mount board from an art supplier do the job. The posting side of prints, including tubes, canvases and framed work, is covered in our artwork packaging guide.

Which board back envelope keeps cards flat in the post?

Choose the board back envelope one size bigger than the card's own envelope: C5 (229 x 162mm) for A6 and 5 x 7 inch cards, and C4 (324 x 229mm) for A5 cards and A4 prints. A board back envelope has a stiff board panel as its back and a printed Do Not Bend warning, so a card arrives flat where a plain paper envelope would let it fold.

You go one size up because of the card's own envelope. The C sizes match the A paper sizes, so a C6 board back envelope (162 x 114mm) takes an A6 card (105 x 148mm). But an A6 card usually ships with its own C6 envelope, and one C6 envelope will not slide comfortably inside another. The same thing happens with an A5 card in its C5 envelope. If you post the card with its envelope, and most sellers do, size the outer to the envelope.

Best for single cards and flat prints

Board Back Envelopes (Do Not Bend)

A stiff board back keeps prints, papers and cards flat, and the Do Not Bend print tells whoever handles it to take care.

• C4 (324 x 229mm) and C5 (229 x 162mm) in boxes of 125
• C6 (162 x 114mm) in boxes of 250
• Price per box falls as you order more boxes

From £12.00 ex VAT (£14.40 inc VAT)

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A card in a C5 or C4 outer has room to slide about. That does no harm to the card, but if you want it held still, put it in its OPP bag first, or fold a sheet of paper around it. Board back envelopes are from £12.00 ex VAT (£14.40 inc VAT) a box.

A Do Not Bend print is only a request to whoever handles the envelope, and it is the board back that keeps the envelope rigid. For how board backs compare with capacity mailers and the other postal envelopes we stock, see the postal envelopes guide. If your prints are mostly A4, the A4 and C4 envelopes guide goes into that size.

When is a large letter box better than an envelope for cards?

Use a large letter box when the order is a stack of cards, a card with a badge or pin, or anything where the corners need protecting on all sides. A board back envelope is stiff on one face. A die cut cardboard box is rigid all round, and at 20mm deep it stays within the Royal Mail Large Letter thickness limit of 25mm.

Our PIP large letter boxes come in five footprints, all 20mm deep, in packs of 50 from £5.00 ex VAT (£6.00 inc VAT). Three of them matter for card sellers:

• C6 (163 x 112 x 20mm): greeting cards and A6 prints. A small stack of A6 cards with envelopes sits flat inside.
• C5 (229 x 159 x 20mm): an A5 item (148 x 210mm) lies flat, so this takes A5 cards, 5 x 7 inch cards and A5 prints.
• C4 (325 x 225 x 20mm): an A4 item (210 x 297mm) lies flat, for A4 prints and larger card sets.

How many cards fit depends on your card stock and envelopes, so we cannot give you a number. Stack one order, press it lightly and measure the height. If the stack with its bag is under 20mm, the box will close flat. If the lid bulges, the box is past its 20mm depth and may go over the 25mm Large Letter limit, which can mean it is charged at a parcel rate. Split the order across two boxes or move up to a cardboard box.

Best for card bundles and cards with extras

Royal Mail PIP Large Letter Boxes

Each box arrives as a flat blank and folds up by hand, so a pack of 50 takes little shelf space.

• C6 (163 x 112 x 20mm) for A6 cards
• C5 (229 x 159 x 20mm) for A5 and 5 x 7 inch cards
• C4 (325 x 225 x 20mm) for A4 prints

From £5.00 ex VAT (£6.00 inc VAT)

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Our large letter boxes guide goes through what fits a PIP box and how to stay inside the limits.

How do you pack wholesale bundles of cards for shops?

Bag each card with its envelope, group the cards by design, wrap each group in kraft paper and pack the groups flat in a cardboard box with paper filling the gaps. A shop wants to open the box and put stock straight on the rack, so every card should arrive bagged, flat and sorted.

1. Bag every card. One card and one envelope per OPP bag, sealed the same way each time so the rack looks uniform.
2. Group by design. Shops usually order cards in sixes or dozens of a design. Stack each design together, all facing the same way.
3. Wrap each group. A band or full wrap of kraft paper stops the bags sliding against each other and scuffing. Write the design name and quantity on the paper.
4. Pick a box close to the card footprint. The cards should lie flat with little room to move sideways. A box that is much bigger than the cards lets the stacks shift and the corners take the knocks.
5. Fill the gaps. Scrunch kraft paper into any space at the sides and on top until nothing moves when you shake the closed box gently.
6. Add the paperwork and seal. Put the delivery note on top, close the flaps and tape along the centre seam.

For the wrapping and void fill, our kraft paper rolls come in three types. The centre-feed roll in a dispenser box, 200mm x 250m in 70gsm, is the narrow one made for small parcels and sits on the bench feeding paper from the middle. The 375mm x 300m centre-feed roll, also 70gsm, suits bigger boxes. The standard 500mm x 200m roll is a heavier 90gsm and is the widest. Kraft paper rolls are from £25.00 ex VAT (£30.00 inc VAT) a roll, and one roll lasts a card seller a long time. If you only send a wholesale order now and then, you do not need to buy a roll, because clean paper you already have does the same job.

For the outer, look at our single wall cardboard boxes, from £0.35 ex VAT (£0.42 inc VAT) each, and choose a size from the product page that matches your card stacks. A very small wholesale top up, say a dozen cards, may still fit a C4 PIP large letter box if the stack is under 20mm. More on kraft paper as void fill is in the kraft paper rolls guide.

Shop kraft paper rolls

How much should you buy, and what does it cost per card?

Start with one pack of 100 OPP bags in the size that fits your most common card, one box of board back envelopes and one pack of 50 large letter boxes, then reorder in multiples once you know your monthly volume. Every product here is sold by the single pack, box or roll, so there is no large minimum to meet.

The from prices are for the lowest priced size in each range, and larger sizes cost more, so check the size you need on the product page. Many of these products have volume pricing: the price per pack falls as you buy more, and the tiers are shown on each page. If you post cards every week, buying several packs at once brings the cost per card down, and a trade account is worth setting up. A VAT invoice comes with every order.

• Delivery: Royal Mail Tracked 48 is free on every order with no minimum.
• Dispatch: orders placed by 2pm Monday to Friday leave our Manchester unit the same working day.
• Collection: free click and collect from Cheetham Hill, Manchester, usually ready within 2 hours.
• Local van: same-day van delivery within 10 miles of Cheetham Hill. Details are on the local delivery page.

Before a busy card season, order early enough that a second pack is on the shelf before the first runs out. Our peak season packaging checklist has a stock plan for the run from Black Friday to Christmas. You can browse the full ranges in bags, boxes and protective packaging, or ring 0161 706 1246 or use the contact page if you want to check a size before ordering.

Frequently Asked Questions

What size cello bags do I need for greeting cards?

For A5 and 5 x 7 inch greeting cards, our 6.5 x 9 inch (165 x 230mm) OPP bag fits the card with its envelope behind. For an A5 card with a full C5 envelope or a thick set, the 8 x 10 inch (203 x 254mm) bag gives more room. For A6 and small square cards, the 6.5 x 9 inch bag is larger than a snug sleeve, so you fold the spare over the back and fix it with a sticker.

Does Pack Solution sell small self-seal card sleeves?

No. Pack Solution does not stock small self-seal card sleeves sized closely to A6 or 5 x 5 inch cards. Our smallest clear OPP bag is 6.5 x 9 inches (165 x 230mm), and our listing does not state a self-seal strip, so plan to close the bag with a sticker or clear tape.

Are cello bags and cellophane bags for cards the same as OPP bags?

In everyday use, yes. Card sellers and shops use cello bags and cellophane bags as names for clear, glossy card bags, and the bags we stock under those names are made from polypropylene, known as OPP. Our transparent OPP bags come in 10 sizes in packs of 100.

How do I post a greeting card so it does not bend?

Post the greeting card in a board back envelope, which has a stiff board back and a printed Do Not Bend warning. Choose the envelope one size bigger than the card's own envelope: C5 (229 x 162mm) for an A6 or 5 x 7 inch card, and C4 (324 x 229mm) for an A5 card. For several cards in one order, a 20mm deep PIP large letter box protects all the edges.

Can I send greeting cards as a Royal Mail Large Letter?

Greeting cards can go as a Large Letter if the packed item is no more than 25mm thick and inside Royal Mail's other Large Letter limits. Our PIP large letter boxes are 20mm deep, and board back envelopes are thinner than that. Royal Mail's size and weight limits can change, so check the current guide before you price your postage.

What is the best way to pack a wholesale order of greeting cards?

Bag each greeting card with its envelope in a clear OPP bag, stack the cards by design and wrap each stack in kraft paper. Pack the stacks flat in a cardboard box close to the card footprint and fill any gaps with scrunched kraft paper so nothing moves. Put the delivery note on top before you tape the box.

Shop for This Job

• Mailing & Polythene Bags
• Cardboard Boxes
• Protective Packaging

Related Guides

• Cellophane Bags and Cello Bags: OPP Sizes, Uses and Buying Tips
• Plastic Envelopes and Postal Envelopes: Board Back and Capacity Compared
• Artwork Packaging: How to Post Prints, Canvases and Framed Art

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