Tips to Maximize Light-Blocking & Stop Light Leaks from Curtain Edges

 

A thin blade of early-morning light across the pillow is the quickest way to find out where your curtains fall short. Light gets around curtains in four places: over the top of the rod, past the sides, under the hem and, faintly, through the fabric itself. To stop light coming through the top and sides of your curtains, close those gaps rather than simply reaching for a thicker fabric: hang the rod higher and wider than the window, choose a heading that sits close to it, add a blackout fabric or lining, let the hem graze the floor, and seal the top and sides with a valance or a French return. Whether you only want to soften the glare in a living room or need bedroom curtains that keep the room properly dark, a curtain that leaks light is annoying.

Fortunately, there are several means to maximize the light-controlling capacity of your curtains and minimize light leaks around their profiles. This guide arrays key considerations to be made before ordering the drapery, as well as remedial measures that can be embraced after installing the curtains. Whether optimal light-blocking is your forethought or afterthought, you will find reliable styling advice here. So, without further ado, let’s dive in - 

Add Blackout Lining

 

The process of optimizing light control with curtains starts with the selection of the drapery fabric and its lining. Tight-woven thick fabrics should be preferred to provide maximum resistance to incoming light. 

If the goal is a high level of room darkening in a bedroom, nursery or media room for example, opt for blackout curtains, either as the front ‘face’ fabric or as the lining. So, whether you’ve chosen a humble cotton or a stately velvet, the blackout lining can help accomplish a dark, moody ambiance when the curtains are drawn. 

However, there are nuances to this choice that require attention. Blackout lining will be most effective if the choice of face fabric also supports the goal of room darkening. To that end, here are a couple of tips to keep in mind to maximize the room-darkening capacity of your blackout-lined drapes: 

• OPT FOR DARKER COLORS: Darker colors absorb light and block it better than lighter colors that reflect light and bounce it around. So, if you want the highest possible level of room-darkening, choose a dark-hued drapery face fabric, and then support it with blackout lining.
• OPT FOR HEAVIER FABRICS: You can expect a terrific insulator from a heavy cotton or velvet curtain with a blackout lining but not half as much from a loose-woven linen or lightweight cotton. So, choose a tight-knit, thick drapery fabric and then back it with our blackout lining for maximum insulation.

Alternatively, you can choose blackout drapery face fabric itself, which will provide room-darkening even without the use of a blackout lining. And, if you want to accentuate the insulative capacity further, you can also add a blackout lining behind a blackout fabric.

 

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Install the Drapery Rod Higher and Wider

 

Light leaks from the curtain edges compromise the insulative capacity of the curtains, and for someone who needs an evenly darkened room to catch a wink, this can be bothersome. So, one simple technique to plug those leaks is to go for extended coverage on all sides. 

For this, mount your drapery rod/track at least 6 inches above the window trim. Also, extend it beyond the window’s frame by at least 6 inches on each side. This will ensure that the curtains overlap the window frame substantially at the top and the sides, narrowing the gaps through which light leaks in. To close those gaps further at the top and sides, a couple of other ideas can work in tandem, which we explain ahead -

• INSTALL FRENCH RETURN CURTAIN RODS: Mitigating light leaks from the sides of the drapery need not be an afterthought. If you haven’t yet purchased your hardware, consider choosing French curtain rods, also known as self-return curtain rods. These rods do not have finials; instead they turn at a right angle and attach to the wall. Thus the curtains wrap around the window, closing the gap between the curtain and the wall, so far less light bleeds in from the sides.

• USE THE HOOK-AND-EYE METHOD: If you have missed the opportunity to install French curtain rods, worry not. You can still minimize light leaks from the sides by covering the ‘drapery return’ that is, the distance between the wall and the curtain - with a simple hack.

• This simple DIY idea involves screwing in a small screw eye bolt, better known as ‘hook and eye’, on the wall right under the rod where the last pleat’s hook is. Then when hanging the curtains on the rod, feed the last pleat’s hook into the grommet of the screw eye bolt. Thus the curtains will touch the wall on both sides of the window, seamlessly covering the return.

Opt for Floor-Length Curtains

 

Light also leaks from the bottom of the drapery, so being generous with the length helps to enhance the room-darkening capacity of your drapery. Opt for floor-length custom curtains rather than sill-length short curtains. And, for best results, go for the seamless coverage of floor-to-ceiling drapery where light can find no escape. 

Pay special attention to the drop-point. If the curtains float an inch or so above the floor, some light will seep in from under the drapes. For optimal light-blocking from the bottom, ensure that the curtains graze the floor lightly.

For even better results, choose to break-puddle them, that is, extend them by about 1 inch after touching the floor. Thus, the curtains will make seamless contact with the floor, closing the last gap for light leaks. We recommend this drop-point, especially for rooms with uneven floors where floating curtains cannot maintain a uniform finish, thus creating wider gaps at some points. Break-puddling minimizes light leaks and also masks the defect of the unleveled floor.

Splurge on the Width and Ensure ‘Fuller’ Pleats 

 

Curtains, more than any other type of window treatment, are capable of insulating the room because they have something unique: the ‘pleats’. The rippled contours of the drapery bring multiple layers of the fabric at play, thereby multiplying its insulative capacity. In addition, the pleats create air pockets and the air trapped between the folds further enhances the curtains’ volume, and by extension, their capacity to block light.

So, be generous with the width, and you will have ‘fuller’ pleats. And the denser the gather, the more effective your curtains will be at light-blocking. For most headings, that means about 2x fullness: a total curtain width about twice the length of the rod, and never less than 1.5x. Our pinch pleats are an exception: we sew them with 2.5–3x fullness for extra fullness and lush pleats, so you order the finished width using the rod-plus-6-inches rule. For a clearer explanation with examples of calculating the right width, visit our Drapery Measurement Guide. 

Choose a Full-Coverage Heading Style

 

The heading style refers to the design of the curtain header - the top portion that attaches to the rod/track. There are over a dozen heading styles on offer at The White Window, each offering a unique combination of visual appeal and functional traits. Some heading styles are better than others at blocking light, so be wise with the choice when optimal light blocking is a priority.

For maximizing the room-darkening capacity of your drapes, opt for heading styles such as double pinch pleats, flat panel tops, rod pockets, pencil pleats, etc, that feature a continuous coverage of the top without any grommets, gaps or tabs - thereby minimizing chances of light leaks from the top.

Styles such as tab tops, grommet tops and tie tops, on the other hand, feature fabric loops or grommets through which light can pass, making them less-than-ideal options for blackout drapery. 

We recommend referring to our Drapery Headings Style Guide to go through each of the styles in detail before you make your decision.

Install Cornices or Valances

 

If you can incorporate valances, cornices or board-mounted valances into your decor style, note that they can be of immense help to optimize the efficiency of your room-darkening drapery. These add–ons that are often seen primarily as decorative additions, are in fact, great for containing light leaks from above the drapery. They close the gap between the top of the drapery and the wall, so far less light breaks through from above.

For the darkest result of all, layer a blackout roman shade under your curtains: the shade sits close to the glass and the curtains cover its edges. Our sister store, The White Window Shades, explains how to layer roman shades with curtains.

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Blocking Light Leaks: FAQs

How do you stop light coming through the top of curtains?

Hang the rod or track at least 6 in above the window frame, choose a heading that sits close to it, such as pinch pleat, pencil pleat, flat panel or rod pocket, and add a valance, which closes the gap between the top of the curtains and the wall.

How do you stop light coming in at the sides of curtains?

Run the rod at least 6 in past the frame on each side so the curtains overlap the wall, then close the last gap by wrapping the ends back to the wall with a French return rod, or with a hook and eye fixed just under the end of the rod.

Why does light still come through blackout curtains?

Blackout fabrics and linings block most light, but no curtain is completely light-proof, and most of the light you see comes around the edges: over the rod, past the sides and under the hem. Closing those gaps makes more difference than a thicker fabric.

Which curtain heading blocks the most light?

Headings with a continuous top that sits close to the rod or track, such as pinch pleat, pencil pleat, flat panel and rod pocket. Grommet, tab top and tie top curtains hang below the rod and leave small gaps that light can pass through.

How do you stop light coming in under curtains?

Order floor-length curtains that just graze the floor, or add about 1 inch for a slight break so the hem rests on it. On an uneven floor, a break also hides the dips that would leave a floating hem gappy.

Does a valance help block light?

Yes. A valance or board-mounted valance covers the top of the curtains and closes the gap to the wall, so far less light spills over the top. Our valance installation guide shows how a board-mounted valance goes up.

What is a French return curtain rod?

A rod without finials whose ends turn back at a right angle to the wall. The curtain wraps around the end of the rod, closing the gap at the side where light would otherwise creep in.

The Bottom Line

 

Be it the bedroom where you want to unwind at the end of a long grind or the home office where you want to block the sun’s glare on the computer screen, drapes are expected to work to their best in blocking light at your desired level. This function is not met by merely selecting the right fabric, it is rather a team effort where several design decisions harmonize and synchronize to achieve the end goal of optimal light control. We hope that this guide has helped you identify all the key factors at play so that you can maximize the light control capacity of your drapery.

If you’ve just embarked on your decor journey, pay attention to details such as fabric, lining, coverage and so on before placing the order. If you’re trying to enhance the light-blocking capacity of your curtains after ordering and installing them, take steps to close the light leaks around the drapery. And that’s how you maximize the light-blocking capacity of your drapes! Every curtain is made to order in any of our 2,500+ fabrics and handcrafted by artisans in India. If you need help, email us at hi@thewhitewindowcurtains.com.

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