The boxes for soap that work best for posting are small crash lock boxes for orders of two bars or more, and 20mm deep PIP large letter boxes for a single bar that is slim enough to fit. Wrap every bar before it goes in the box, in a clear OPP bag or a sheet of kraft paper, so the oils and the scent stay on the soap and off the cardboard.
This guide is for handmade soap sellers who post their own orders. It covers which box suits one bar, several bars and a gift set, when a bar can go at Large Letter thickness and when it cannot, how to wrap a bar, how to pack a multi-bar order so nothing rubs or rattles, what we do and do not stock for gift packaging, and how much to buy so the soap packaging on each order costs pennies.
In This Guide
- Quick picks for soap sellers
- Which boxes for soap suit single bars, multi-bar orders and gift sets?
- Can you post a single bar of soap as a Large Letter?
- How do you wrap a soap bar so scent and oils stay off the outer box?
- How do you pack a multi-bar order so the bars do not rub or rattle?
- Do we sell gift boxes for soap, or printed and window soap boxes?
- Which soap packaging mistakes cause damaged or marked bars?
- How much soap packaging should you buy, and what does it cost per order?
- Frequently Asked Questions
Quick picks for soap sellers
If you post single bars and small sets, these three cover most orders.
Best for multi-bar orders and sets
Crash Lock Boxes
Cardboard boxes with a base that locks as you open them, so you only close the top.
- Small sizes from CL-A (100 x 100 x 70mm) to CL-E (252 x 136 x 88mm)
- Sold per box, minimum 5 per size
- No tape needed on the base
From £0.59 ex VAT (£0.71 inc VAT)
Choose sizeView product
Best for one slim bar
Royal Mail PIP Large Letter Boxes
Die cut cardboard boxes 20mm deep, which sits inside the Royal Mail Large Letter thickness limit of 25mm.
- Mini (101 x 101 x 20mm) and C6 (163 x 112 x 20mm) suit soap
- Packs of 50, supplied flat
- Fold together by hand
From £5.00 ex VAT (£6.00 inc VAT)
Choose sizeView product
Best inner wrap for bars and sets
Transparent OPP Bags (Polypropylene)
Clear, glossy polypropylene bags that keep the soap on show and away from the cardboard.
- Smallest size 6.5 x 9" (165 x 230mm)
- Packs of 100
- Often sold as cello or cellophane bags
From £2.50 ex VAT (£3.00 inc VAT)
Choose sizeView productWhich boxes for soap suit single bars, multi-bar orders and gift sets?
A single slim bar goes in a 20mm deep large letter box, and anything from two bars up to a gift set goes in a small crash lock box. Those two box types cover nearly every soap order a small maker sends. Which one you need depends on how thick your bar is once wrapped and how many bars are in the order.
Our crash lock boxes have a base that folds in and locks as you open the flat box out, so you only close the top. They are sold per box from £0.59 ex VAT (£0.71 inc VAT), with a minimum of 5 per size. The five smallest sizes are the ones soap sellers need. Our Royal Mail PIP large letter boxes are die cut boxes 20mm deep, in packs of 50 from £5.00 ex VAT (£6.00 inc VAT).
Bars vary a lot between makers, so the table uses an example bar of 80 x 55 x 25mm (about 3.1 x 2.2 x 1 inch). Measure your own bars once wrapped and adjust. Box dimensions are length x width x height.
| Order | Box to use | Size | How it packs |
|---|---|---|---|
| One slim bar, 20mm or less once wrapped | PIP large letter box | Mini, 101 x 101 x 20mm (4 x 4 x 0.8") | Bar lies flat. The wrap has to fit inside the 20mm too. |
| One slim long bar or two slim sample bars | PIP large letter box | C6, 163 x 112 x 20mm (6.4 x 4.4 x 0.8") | Side by side in one layer. |
| One or two standard bars | Crash lock box | CL-A, 100 x 100 x 70mm (3.9 x 3.9 x 2.8") | Two example bars stacked flat, with room for wrap above and below. |
| Two or three bars in a row | Crash lock box | CL-C, 180 x 100 x 50mm (7.1 x 3.9 x 2") | One layer, bars turned sideways, paper on top. |
| Around four bars | Crash lock box | CL-B, 160 x 150 x 75mm (6.3 x 5.9 x 3") | Two layers of two with cushioning all round. |
| Six to eight bars | Crash lock box | CL-D, 220 x 111 x 78mm (8.7 x 4.4 x 3.1") | Two layers of bars turned sideways along the box. |
| Gift set with a soap dish, flannel or bath extras | Crash lock box | CL-E, 252 x 136 x 88mm (9.9 x 5.4 x 3.5") | Bars on one side, extras on the other, paper between. |
The bar counts are a rough guide worked out from the listed box dimensions and the example bar. Before you buy more than the minimum, order 5 of the size you think you need and pack a real order into one.
Do you need a box at all? For a single bar you often do. Soap is solid, but corners chip and a soft, fresh bar dents under pressure, so a mailing bag on its own gives the bar very little protection in a sack of parcels.
Can you post a single bar of soap as a Large Letter?
You can post a single bar of soap as a Large Letter only if the bar and its wrapping together are no more than 25mm thick, which is the Royal Mail Large Letter thickness limit. Every one of our PIP boxes is 20mm deep, so a bar has to be 20mm or less once wrapped to fit one. Many handmade bars are cut thicker than 20mm, so check yours with a ruler before you plan your postage around it.
A bar like the 25mm example above will not go in a large letter box however you wrap it. Do not squeeze it in. A box that bulges past 25mm can be charged at a higher rate, and a soft bar pressed against the lid arrives with the lid's shape in it.
Sellers who want the Large Letter rate usually get there in one of these ways:
- Cut a slimmer bar for posting. A wider, flatter bar of the same weight can sit under 20mm where a chunky one cannot.
- Sell sample slices or guest bars. Thin slices fit the Mini box (101 x 101 x 20mm), and two can share a C6 (163 x 112 x 20mm).
- Keep the wrap thin. One layer of paper or a clear bag adds very little. Honeycomb paper and bubble wrap add several millimetres, so leave them for boxed orders.
Thickness is only one of the limits. A Large Letter also has a maximum length, width and weight, and soap is heavy for its size, so weigh a packed box on kitchen scales and check Royal Mail for the current limits before you set your postage prices. Our guide to large letter boxes and what fits in them goes through the five PIP sizes in detail.
How do you wrap a soap bar so scent and oils stay off the outer box?
Wrap each bar in its own inner layer, either a clear OPP bag or a sheet of kraft paper, before it goes in the postal box. Handmade soap can leave oil marks on bare cardboard, and a strongly scented bar will pass its smell to the box and to anything else packed with it. An inner wrap puts a layer between the soap and the card, and it keeps different scents apart in a mixed order.
We stock both wraps, and they do slightly different jobs.
Our transparent OPP bags are clear, glossy polypropylene bags, the kind many shops call cello bags. They come in packs of 100 from £2.50 ex VAT (£3.00 inc VAT). A film bag stops oil reaching the cardboard and the customer can see the bar through it. Our smallest bag is 6.5 x 9" (165 x 230mm), which is far bigger than a single bar. You can fold the spare film round the bar and hold it with a sticker, but the bag is a better fit for a set of two or three bars, or a bar with a soap dish. The description does not list a self-seal strip, so plan on a sticker or a strip of tape to close it. For more on sizes, see our cellophane and cello bags guide.
Our kraft paper rolls are brown paper you cut to whatever size the bar needs, from £25.00 ex VAT (£30.00 inc VAT) a roll. The centre-feed roll in a box, 200mm x 250m in 70gsm, is the one for soap: 200mm (7.9 inches) is wide enough to go right round a bar, and the box sits on the bench and feeds paper from the middle. Many soap makers prefer paper because a bar wrapped in paper is not sealed in. Paper is not a barrier to oil though, so a very fresh or oily bar may mark it over time.
To wrap a bar in kraft paper:
- Cut a sheet from the 200mm roll about three times the length of the bar. For the 80mm example bar that is roughly 240mm.
- Lay the bar face down in the middle of the sheet, with the long side of the bar running across the width of the paper.
- Bring the two long edges of the paper up to meet over the back of the bar, fold them over together once or twice, and press the fold flat against the soap.
- Fold in the corners at each end to make a point, as you would on a wrapped gift, and fold each point onto the back.
- Hold the folds down with your own product label, or with a short strip of paper tape.
- Turn the bar over. The front is a smooth face of brown paper for a sticker or a stamp.
If you want paper closures all the way through, our kraft paper tape comes in packs of 6 rolls from £14.00 ex VAT (£16.80 inc VAT). The 48mm x 50m roll is wide for a soap bar, so cut short pieces and split them lengthways.
Best for paper-wrapped bars
Kraft Paper Rolls
Brown kraft paper for wrapping each bar and filling gaps in the box.
- Centre-feed roll in box, 200mm x 250m, 70gsm
- Also 375mm x 300m (70gsm) and 500mm x 200m (90gsm)
- Sold as single rolls
From £25.00 ex VAT (£30.00 inc VAT)
Choose sizeView productWhat we cannot tell you. We make no claim that any of our packaging has been tested for direct contact with soap or other cosmetic products, or that a bag holds scent in completely. If contact safety matters for your product, check the rules that apply to you. Some makers put a layer of greaseproof or wax paper next to the soap first. We do not stock either.
How do you pack a multi-bar order so the bars do not rub or rattle?
Wrap every bar separately, pack the bars tight against each other in a crash lock box, and fill what is left with paper so nothing moves when you shake the box. Soap does not smash like glass, but bars that slide about knock their corners off, scuff their labels and rub scent onto each other, so a snug fit does more for them than thick padding.
For cushioning, our honeycomb paper rolls are 80gsm paper that opens into a honeycomb pattern when you stretch it. Rolls are 250m long, 395mm or 500mm wide, from £28.00 ex VAT (£33.60 inc VAT). The 395mm width is the one the product page suggests for jars and cosmetics, and it suits soap for the same reason: a narrower sheet is easier to handle round small items.
We would pack a four-bar order like this:
- Open a CL-B crash lock box (160 x 150 x 75mm). The base locks by itself.
- Line the bottom with a sheet of kraft paper or a stretched piece of honeycomb paper.
- Put two wrapped bars side by side on the base. Put the heaviest bars at the bottom.
- Lay a single sheet of paper over them, then add the second layer of two bars.
- Push scrunched kraft paper down the sides and into the space above until the bars cannot shift.
- Close the lid and shake the box gently. If you hear or feel movement, open it and add more paper.
- Seal the top with tape or a label, and add the address label.
Mixed scents need a little more care. Peppermint next to lavender for a week in a sealed box will swap smells if both bars are only in paper. Put the strongest scented bars in OPP bags, or bag each scent separately, and keep unscented bars away from the strong ones.
Soap is dense, so a full box weighs more than it looks. If you are filling a CL-D or CL-E box with bars, pick it up by one end before you seal it. A box that sags or bows needs splitting into two smaller boxes. We do not publish weight ratings for these boxes and will not guess at one here.
Bubble wrap also works, and our small bubble wrap costs less per roll, from £9.00 ex VAT (£10.80 inc VAT) for 100m. The choice is mostly about what you want your customer to find when they open the box. Our comparison of how to use honeycomb paper and how much you need covers the wrapping method. If you also send candles or wax melts with your soap, the candle and wax melt packaging guide deals with the glass, which needs far more protection than a bar does.
Best for cushioning boxed sets
Honeycomb Paper Rolls (80gsm)
Paper that stretches into a honeycomb cushion round bars, dishes and jars.
- 80gsm paper on 250m rolls
- 395mm or 500mm wide
- Single rolls available
From £28.00 ex VAT (£33.60 inc VAT)
Choose sizeView productDo we sell gift boxes for soap, or printed and window soap boxes?
No. We do not sell gift boxes for soap, printed soap boxes or window boxes. Pack Solution stocks plain packaging only, and nothing in our range is a retail soap carton with a cut-out window or your logo printed on it. If that is what your brand needs, you will have to buy it from a carton printer or a gift box supplier, and use our boxes as the outer for posting.
Plain stock still makes a tidy gift set. The crash lock product page describes the boxes as neat enough for products, samples and gift boxes, and a plain brown box is a blank surface for your own sticker or stamp. This is how small makers usually build a gift set from what we do stock:
- The box. A CL-B, CL-D or CL-E crash lock box, with your own label on the lid.
- The bars. Each one wrapped in kraft paper with your product label, or the whole set together in one clear OPP bag so the customer sees it as soon as the lid opens.
- The lining. A stretched sheet of honeycomb paper under and over the bars.
- The outer. If the gift box needs to arrive clean, put it inside a mailing bag or a slightly larger box so the postage label and the tape go on the outer layer.
People searching for boxes of soap are often after a ready-made boxed set to buy as a present. If you sell those, the box the customer keeps and the box the courier handles do different jobs, and the courier's box is the one we can help with.
For your own stickers, we sell blank A4 sheet labels that go through an office printer. We do not sell label printers and we do not print labels for you. On what your label has to say: soap sold to the public is usually covered by rules on labelling cosmetic products, and we are a packaging supplier, so we cannot advise on them. Check the current labelling rules for cosmetic products yourself before you design a label or a wrap.
Soap packs in much the same way as other small beauty products. Our cosmetic and skincare packaging guide covers jars, bottles and tubes, and the jewellery packaging guide is useful if you also post very small items that suit the Mini box.
Which soap packaging mistakes cause damaged or marked bars?
The most common soap packaging mistakes are posting a bare bar in a cardboard box, choosing a box with too much empty space, and forcing a thick bar into a 20mm box. All three are cheap to fix.
- Bare soap against cardboard. The card can pick up oil marks and scent, and the bar picks up fibres and dust. Always wrap the bar first.
- A box that is too big. A single bar loose in a CL-E box will slide from end to end. Use the smallest box the order fits in and fill the rest with paper.
- A bulging large letter box. If the lid does not close flat, the bar is too thick for it. Move up to a CL-A crash lock box.
For a wider list that applies to any product, see our guide to parcel packaging mistakes.
How much soap packaging should you buy, and what does it cost per order?
Start with one pack of 50 large letter boxes if your bars fit them, 5 to 10 crash lock boxes in the one or two sizes your orders need, one pack of 100 OPP bags and one roll of kraft paper. That is enough to post your first few dozen orders and find out which sizes you really use, without tying up money in boxes that turn out to be the wrong shape.
Worked from the lowest listed prices, the packaging on one order costs very little:
| Item | Pack | From price ex VAT | Works out at |
|---|---|---|---|
| PIP large letter boxes | Pack of 50 | £5.00 (£6.00 inc VAT) | 10p a box ex VAT at the from price |
| Crash lock boxes | Per box, minimum 5 | £0.59 (£0.71 inc VAT) | 59p a box ex VAT at the from price |
| Transparent OPP bags | Pack of 100 | £2.50 (£3.00 inc VAT) | 2.5p a bag ex VAT at the from price |
| Kraft paper roll | 1 roll, 200m to 300m | £25.00 (£30.00 inc VAT) | Hundreds of bar wraps from one roll |
| Honeycomb paper roll | 1 roll, 250m | £28.00 (£33.60 inc VAT) | Depends on how much you use per box |
The from price is the lowest price in each range, so larger sizes cost more. Check the product page for the price of the exact size you need. On the 200mm x 250m kraft roll, a 240mm sheet per bar gives you around a thousand wraps from one roll, which is why paper is the cheapest inner wrap per bar once you are past the first few months.
Most of these products have volume pricing. The price per box or per pack falls as you buy more, and the tiers are shown on each product page. Once you know your regular sizes, buying a few months of boxes in one order brings the cost of each one down. Store flat boxes somewhere dry, away from the soap, so the card does not pick up scent before you use it.
Royal Mail Tracked 48 delivery is free on every order with no minimum. Orders placed by 2pm Monday to Friday leave our Manchester unit the same working day. If you are local, click and collect from Cheetham Hill is free and usually ready within 2 hours, and we run same-day van delivery within 10 miles. Every order comes with a VAT invoice.
If you post soap every week, a trade account is worth setting up. If you are not sure which box fits your bar, measure a wrapped bar, then call 0161 706 1246 or use the contact page and we will tell you which size we would try first. You can also browse all protective packaging and mailing and polythene bags.
Frequently Asked Questions
What are the best boxes for soap when you sell online?
The best boxes for soap sold online are small crash lock boxes for orders of two bars or more, and 20mm deep PIP large letter boxes for a single slim bar. Crash lock boxes run from CL-A (100 x 100 x 70mm) upwards and are sold per box with a minimum of 5 per size. PIP large letter boxes come in packs of 50. Wrap each bar before it goes in either box.
Can a bar of soap be posted as a Royal Mail Large Letter?
A bar of soap can be posted as a Large Letter only if the bar and its wrapping are no more than 25mm thick in total, and no more than 20mm to fit our large letter boxes. Many handmade soap bars are cut thicker than 20mm and will not fit a large letter box. Large Letters also have length, width and weight limits, so check Royal Mail for the current figures and weigh a packed box before you set your postage price.
Do you sell gift boxes for soap or printed soap boxes?
No, Pack Solution does not sell gift boxes for soap, printed soap boxes or window boxes. We sell plain stock packaging only. Soap sellers use our plain crash lock boxes with their own sticker on the lid for gift sets, or as the outer postal box around a retail carton bought elsewhere.
How do I stop soap scent and oil getting onto the postal box?
Wrap each soap bar in its own inner layer before it goes in the postal box. A clear OPP bag puts a layer of film between the soap and the cardboard, and a sheet of kraft paper keeps the bar off the card while leaving it unsealed. We have not tested any of our packaging for contact with soap, so we make no claim that a bag holds scent in completely.
What size box holds four bars of soap?
A CL-B crash lock box (160 x 150 x 75mm) holds around four bars of soap in two layers of two, based on an example bar of 80 x 55 x 25mm, with room for paper cushioning. Soap bar sizes vary between makers, so measure your own wrapped bars. Order the minimum of 5 boxes and pack a real order before you buy more.
What has to be printed on soap packaging?
Soap sold to the public is usually covered by rules on labelling cosmetic products, and Pack Solution cannot advise on those rules. Check the current labelling requirements for cosmetic products yourself before you design a label or a wrap. We supply blank A4 sheet labels and plain packaging, and we do not print labels or boxes.
