If a nurse has been covering a wound with a smooth, skin-coloured patch and you now need more, it may well be a hydrocolloid dressing, and two of the most common brands are DuoDERM (ConvaTec) and Comfeel Plus (Coloplast). Both work the same way, and the best one to reorder is the exact version and size printed on your box. In short: DuoDERM Extra Thin and Comfeel Plus Transparent are thin sheets for little fluid or skin protection; DuoDERM CGF and Comfeel Plus Ulcer are standard sheets for more fluid; DuoDERM Signal adds a tapered border and a change line.
This is general product information, not medical advice. Your nurse, NSWOC (a nurse specialized in wound, ostomy and continence care), doctor or pharmacist should choose the dressing and the care plan. Always follow the manufacturer's instructions.
What a hydrocolloid dressing does for wounds
A hydrocolloid dressing is a flexible wafer of gel-forming particles (in DuoDERM's case cellulose, pectin and gelatin) under a thin waterproof film. It sticks on by itself. As it takes up wound fluid, the particles swell into a soft gel, and the sealed (occlusive) top layer keeps the wound moist while shutting out water, dirt and friction. Common examples of hydrocolloid dressings are DuoDERM and Comfeel Plus; the small "hydrocolloid bandages" sold for blisters use the same idea.
Two things surprise people. The gel shows through as a pale bubble, which is expected. And there may be a smell at changes: ConvaTec notes that wound odour isn't necessarily a sign of infection, and that a wound can look bigger at first under an occlusive dressing. If you're worried, ask your nurse.
The DuoDERM family: CGF vs Extra Thin vs Signal
ConvaTec's DuoDERM comes in three main dressing sheets, and they aren't interchangeable:
- DuoDERM Extra Thin: a thin, translucent sheet with no border. ConvaTec lists it for superficial wounds, dry to lightly draining ulcers, post-operative wounds, and as a protective dressing; a BC nursing product sheet adds reddened skin. It's what most people mean by a thin hydrocolloid dressing.
- DuoDERM CGF: the standard-thickness sheet, with no border, for light to moderate fluid. It can be cut and worn for up to seven days. ConvaTec labels it for minor cuts, scrapes, skin tears and minor burns, and, under professional supervision, for leg ulcers, pressure injuries and surgical wounds.
- DuoDERM Signal: bordered, with a tapered edge and a low-friction top film that resists rucking up on bedding. A green line printed on top shows when it's time to change. Shapes include a sacral (tailbone) butterfly and an oval.
DuoDERM Extra Thin: 4 × 4, 6 × 6 and 3 × 3 in sheets
Duoderm Extra Thin Cgf Hydrocolloid Dressing, Sterile, 10 cm x 10 cm (4in x 4in) (Box of 10)$119.90Shop now
Duoderm Extra Thin Cgf Hydrocolloid Dressing, Sterile, 15 cm x 15 cm (6in x 6in) (Box of 10)$231.76Shop now
Duoderm Extra Thin Cgf Hydrocolloid Dressing, Sterile, 7 cm x 7 cm (3in x 3in) (Box of 20)$193.47Shop now
CGF or Signal on your box? See the buying section below.
The Comfeel Plus family: Ulcer, Transparent, Sacral and Contour
Coloplast's Comfeel Plus is a hydrocolloid with calcium alginate blended in to hold more fluid, for low to moderate amounts of exudate (wound fluid), according to the WoundSource product listing. Its smooth surface reduces shear and friction, and it can be cut and comes off in one piece.
- Comfeel Plus Ulcer: the standard sheet.
- Comfeel Plus Transparent: a thin, clear version without alginate, so you can see the wound without lifting it.
- Comfeel Plus Sacral: shaped to fit over the tailbone.
- Comfeel Plus Contour: shaped for awkward spots such as heels and elbows (see sizes below).
DuoDERM vs Comfeel Plus: hydrocolloid dressing comparison
There's no single best hydrocolloid dressing; at each thickness the two brands are close equivalents. Based on maker information and BC nursing sheets:
| Dressing | Build | Fluid level | Sizes we carry |
|---|---|---|---|
| DuoDERM Extra Thin | Thin, translucent, no border | Dry to light | 7×7–15×18 cm + strips |
| DuoDERM CGF | Standard, no border | Light to moderate | 10×10–20×29 cm |
| DuoDERM Signal | Standard, tapered border, change line | Light | 10×10–20×23 cm, oval, sacral |
| Comfeel Plus Ulcer | Standard, with alginate | Low to moderate | 4×6–20×20 cm |
| Comfeel Plus Transparent | Thin, clear | Low | 5×7–15×15 cm |
| Comfeel Plus Sacral | Standard, shaped | Low to moderate | 18×20 cm |
Comfeel Plus: Transparent and Ulcer 4 × 4 in, plus the Sacral shape
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Hydrocolloid dressing sizes: 4x4 vs 6x6, sacral and heel shapes
The size on the box is the whole sheet, and a hydrocolloid must grip healthy skin to seal. ConvaTec and the BC sheets advise at least 3 cm (about 1¼ in) of overlap on every side, so a 4 × 4 in (10 cm) sheet suits a wound up to roughly 4 cm across. Your nurse will have allowed for this, so reorder what they used.
- Match centimetres, not inches. The DuoDERM CGF "6 × 6 in" is 14 × 14 cm; the Extra Thin "6 × 6 in" is 15 × 15 cm.
- Long or narrow wounds. Rectangles run up to 20 × 29 cm, and Extra Thin also comes in 5 × 10 and 5 × 20 cm strips.
- Sacral shapes. We carry the DuoDERM Signal Sacral (8 × 9 in) and Comfeel Plus Sacral (18 × 20 cm). If incontinence is involved, keeping that skin dry matters too; our underpads guide covers bed protection.
- Heels. We don't carry the DuoDERM Signal heel shape. Comfeel Plus Contour is shaped for heels and elbows; contact us to confirm its size. Bordered foam heel dressings are another option; ask your nurse first.
- Sheets, not rolls. Everything here is a sterile sheet rather than a hydrocolloid dressing roll; DuoDERM CGF and Comfeel Plus can be cut to shape instead.
How to apply and when to change a hydrocolloid dressing
Follow your nurse's plan and the box leaflet. ConvaTec's instructions and the BC nursing sheet for DuoDERM Signal boil down to:
- Prepare. Wash your hands, clean the wound as your nurse showed you, and pat the surrounding skin dry.
- Apply. Peel off the backing and lay the dressing on without stretching, overlapping healthy skin by about 3 cm. Hold your palm over it for a minute or two; hydrocolloids stick best when warm.
- Check daily. Look at the gel bubble and the edges.
- Change it when the bubble nears the edge (on Signal, when any part reaches the change line), if it leaks, rolls or lifts, if it's uncomfortable, or at your nurse's day limit. ConvaTec's maximum is seven days; the BC sheets suggest five to seven.
- Remove gently. Press down on the skin, lift an edge, and peel low and sideways, not straight up. An adhesive remover can help.
When a hydrocolloid dressing isn't the right choice
Makers and nursing references say hydrocolloids aren't for:
- wounds with a lot of fluid (the BC sheets rule out moderate to large amounts for the thin and Signal versions);
- untreated, clinically infected wounds (ConvaTec allows use on infected wounds only under a health professional's care);
- deep wounds that tunnel, or that expose tendon or bone;
- anyone allergic to the dressing or its components.
Call your nurse, NSWOC or doctor promptly, or 811 in many provinces, for spreading redness, swelling or warmth, worsening pain, pus or red streaks, a fever, or a wound that keeps getting bigger or deeper. If someone is very unwell or confused, call 911.
Hydrocolloid vs foam: when Mepilex or Allevyn fits better
If a wound drains more than a hydrocolloid can hold, the skin around it is fragile, or a heel needs cushioning, nurses often move to a silicone foam: it absorbs more and lifts off gently. If you're weighing DuoDERM against Allevyn, or a hydrocolloid against Mepilex, our Mepilex vs Allevyn guide compares both foam families. Check with your nurse before switching.
What public reviewers say about DuoDERM
In public reviews on Amazon.ca and other retailers, buyers like that DuoDERM grips well yet usually comes off without much pain, copes with showers and lasts several days. One DuoDERM Extra Thin listing on Amazon.ca showed 4.6 out of 5 from 958 ratings when we checked in October 2026. Common gripes: the price per dressing, and edges that roll or lift, especially Extra Thin in damp spots such as inside an incontinence brief. Warming it in place and a 3 cm margin help; ask your nurse whether a Signal or sacral shape suits that area.
Which hydrocolloid dressing should you buy?
- Box says DuoDERM Extra Thin: the Extra Thin set earlier in this guide, in the same centimetre size.
- Box says Comfeel Plus: the Comfeel Plus set under the comparison table. Ulcer and Transparent are different thicknesses, so match the word on the box.
- Box says DuoDERM CGF or Signal: the set right after this list. Don't swap one for the other without asking; only Signal has a border and change line.
- Nurse okayed a brand switch: Extra Thin and Comfeel Plus Transparent are the closest thin pair; CGF and Comfeel Plus Ulcer the closest standard pair.
- Not sure? Send us the name and size on your box and we'll match it. Opened wound care products can't be returned, so we'd rather help you get it right first.
DuoDERM Signal and CGF: 4 × 4 in boxes of 5, plus a 6 × 8 in CGF
Buying hydrocolloid dressings in Canada
Standard shipping across Canada is $7, free on orders of $100 or more, and takes 3–5 business days; Express is $20 for 1–2 business days. Orders are processed in 1–2 business days, packed in plain, unmarked boxes, and tracking is emailed. At current prices, every DuoDERM dressing box and Comfeel Plus Ulcer or Sacral box we carry clears free shipping on its own; so do two Comfeel Plus Transparent boxes in any size but the smallest.
Hydrocolloid dressing FAQ
How often should you change a hydrocolloid dressing?
Usually every few days, as your nurse directs: up to seven days for DuoDERM per ConvaTec, or five to seven per the BC sheets. Change sooner if the bubble reaches the edge or the dressing leaks or lifts.
Can you use a hydrocolloid dressing for burns or blisters?
ConvaTec lists minor scalds and burns among DuoDERM's uses, and second-degree burns only under a health professional's care. A burn that is large or deep, or on the face, hands, feet, genitals or a joint, should be seen by a doctor first. For a small friction blister, ask a pharmacist about a blister plaster.
Alginate dressing vs hydrocolloid: what's the difference?
An alginate is a soft, fibrous seaweed-based pad that soaks up a lot of fluid and needs a cover dressing. A hydrocolloid is a self-adhesive sheet for light to moderate fluid. Comfeel Plus sits in between. For heavily draining wounds, nurses tend to choose alginates or foams; we carry Kaltostat and Biatain Alginate in our wound care collection.
Can you put a hydrocolloid dressing on an infected wound?
Not on your own. The BC sheets say not to use one on an untreated, clinically infected wound, and ConvaTec allows it only under a health professional's care. If you see signs of infection, call your nurse or doctor before the next change.
The bottom line
DuoDERM and Comfeel Plus are close equivalents. Reorder the exact version and centimetre size on your box, change it when the bubble nears the edge or your nurse says so, and call them about any sign of infection.
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