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Shadow Gap Ceiling With or Without LED: Which System Do You Need?
The easiest way to choose a ceiling shadow-gap system is to ignore the lighting for a moment.
Look at the perimeter in section. Do you want a dark reveal only, a reveal that can also carry concealed light, or a separate light line cut into the plasterboard surface? Those are three different details.
ASP Profiles has products for all three, but the model groups are not interchangeable.
If you want the shadow line only
For a fixed perimeter reveal without LED, the choice inside the C-4 family is straightforward:
| Model | Fixed reveal | LED integration |
| C-4-7 | 7 mm | No |
| C-4-12 | 12 mm | No |
C-4-7 produces the narrowest fixed reveal in the range. C-4-12 gives the perimeter more visual weight while remaining a non-LED detail.
These two versions make sense when the shadow itself is the architectural feature. There is no reason to move to a larger LED-compatible section if the project does not need concealed lighting.
If the perimeter also needs concealed LED
Here the shortlist changes.
ASP Profiles has several ceiling systems that are designed to work with concealed LED integration:
| Model | Shadow-gap geometry | LED compatibility |
| C-1 | Wall offset set during installation | Yes |
| C-2 | Fixed 25 mm reveal | Yes |
| C-2M | Fixed 21 mm reveal | Yes |
| C-4-16 | Fixed 16 mm reveal | Yes |
| C-4-20 | Fixed 20 mm reveal | Yes |
C-2 is not a non-LED alternative. It is a fixed 25 mm shadow-gap ceiling system that is fully compatible with concealed LED integration.
That gives C-2 a clear place in the range: use it when a 25 mm perimeter reveal suits the design and the junction also needs the option of concealed light.
View the C-2 fixed 25 mm LED-compatible system
C-2M is the smaller fixed alternative at 21 mm and is intended for 12.5 mm plasterboard.
C-4-16 and C-4-20 give you fixed 16 mm and 20 mm reveals. They are useful where the perimeter needs to stay more compact than C-2 or C-2M.
C-1 works differently from all of them. Its wall offset is established during installation rather than being defined by one fixed reveal width.
If the light crosses the ceiling, stop looking at perimeter profiles
A line running through the middle of a ceiling is not a shadow-gap detail.
C-3-21 and C-3-41 create recessed linear light lines within the plasterboard plane. Their working widths are 21 mm and 41 mm.
That distinction is easiest to see on a reflected ceiling plan:
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line around the room edge → shadow-gap ceiling system;
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line through the ceiling or wall surface → C-3 linear lighting profile.
The important comparison is the section, not the photograph
An illuminated photograph can make several different systems look similar. The section shows what you are actually specifying.
For a fixed reveal, compare the stated widths directly:
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16 mm – C-4-16;
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20 mm – C-4-20;
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21 mm – C-2M;
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25 mm – C-2.
If the project needs a wall offset that is set on site, C-1 belongs in a separate comparison because the geometry is not fixed in the same way.
The visible reveal still exists when the light is switched off, so its proportion should work as part of the ceiling detail in its own right.
What ASP Profiles supplies – and what remains part of the lighting design
ASP Profiles supplies the aluminium ceiling system.
The LED strip, driver, controller, wiring and electrical design are separate from the aluminium profile. Selecting an LED-compatible C-2, C-2M, C-1 or C-4 version does not mean those electrical components are included.
That separation is useful at specification stage: first define the architectural junction, then coordinate the lighting package with it.
Quick selection guide
Choose by the result you need:
7 or 12 mm dark reveal, no LED: C-4-7 or C-4-12.
16 or 20 mm fixed reveal with concealed LED integration: C-4-16 or C-4-20.
21 mm fixed reveal with concealed LED integration: C-2M.
25 mm fixed reveal with concealed LED integration: C-2.
Installation-set wall offset with concealed LED integration: C-1.
Light line inside the plasterboard surface: C-3-21 or C-3-41.
Explore ASP Profiles ceiling systems
Frequently asked questions
Is C-2 suitable for concealed LED integration?
Yes. C-2 is fully LED-compatible and forms a fixed 25 mm perimeter shadow gap.
Which C-4 versions are non-LED?
C-4-7 and C-4-12.
Which C-4 versions support concealed LED integration?
C-4-16 and C-4-20.
Does C-3 replace a shadow-gap ceiling profile?
No. C-3 creates a recessed light line within the plasterboard surface rather than the wall-to-ceiling perimeter.