Simple lined or unlined curtains are one of the most forgiving home-sewing projects because most of the work is straight measuring, cutting and stitching. The part that causes trouble is usually not the sewing machine; it is getting the finished size right after allowing for hems, headings and the way the curtains gather across the window. Measure the pole or track first, decide how full you want the curtains to look, then calculate the fabric before cutting anything.
Decide where the curtains will finish
Measure from the point where the curtain will hang to the desired finished length.
Common finishes are:
- just below the sill;
- to the radiator or apron;
- just above the floor;
- lightly touching or pooling on the floor.
For pencil pleats, the hook row and whether you use a pole or track determine the correct starting point for the finished drop. For pencil-pleat or other tape headings, measure from the hook position or track according to the tape and fittings you plan to use. Do not assume every heading begins at the same point.
Work out the finished width
Measure the full pole or track width, excluding decorative finials. Curtains normally need more fabric than that measurement because they gather or pleat when closed. For pencil-pleat curtains, plan on roughly twice the pole or track width in flat fabric; some deeper pencil-pleat tapes call for around 2.5 times. Check your specific heading tape before buying fabric, especially for a wide window. For a pair, split the total flat fabric width between the curtains and account for any centre overlap and side returns. Check that the final gathered widths actually cover the track.
Check the heading-tape instructions before buying fabric because they often state the recommended fullness.
Calculate the fabric
Once you know the finished drop, add allowances for the top heading and bottom hem. A generous double hem at the bottom helps curtains hang well. If the fabric has a pattern repeat, allow extra length so the pattern can be matched across multiple widths. For wide windows, each curtain may need more than one fabric width joined together. Calculate the number of full drops needed, multiply by the cut length and then add extra for pattern matching and mistakes.
Buying a little extra from the same dye lot is safer than discovering later that another length of the fabric is slightly different.
Pre-shrink washable fabric
If the curtain fabric is washable and likely to shrink, pre-wash it according to the manufacturer's care instructions before cutting. Dry and press it in the same way you expect to care for the finished curtains. Do the same with lining if appropriate. Some furnishing fabrics should not be machine washed, so do not pre-wash automatically. Follow the fabric care label.
Square the fabric before cutting
Lay the fabric on a large clean surface. Straighten the cut edge using the weave, selvedge or pattern as a guide. Measure the cut length accurately. For patterned material, mark the same pattern point on each drop so adjacent panels match once sewn. Use tailor's chalk, removable fabric marker or pins. Cut with sharp fabric scissors or a rotary cutter and mat. A crooked first cut creates a crooked hem later.
Join widths if necessary
For a curtain wider than one fabric width, place two panels right sides together along the long selvedge edges. Pin or clip. Stitch a straight seam using an appropriate seam allowance. Press the seam open. If making a pair, think about where the joined widths will sit. On patterned fabric, matching the pattern across the seam is more important than using every centimetre of cloth.
Trim excessive selvedge bulk if the fabric manufacturer or sewing method calls for it.
Make the side hems
Turn each side edge towards the wrong side. A common simple finish is a double-fold hem so the raw edge is hidden. Press the first fold, fold again and press once more. Pin in place. Stitch close to the inner folded edge using a straight stitch. Keep the stitching distance consistent from top to bottom. Do not pull the fabric through the machine. Let the feed dogs move it so the side seam does not pucker.
Make the bottom hem
Hang is improved by a deeper bottom hem than side hem. Turn the raw edge up, press it, then turn again to create a double hem. Check the finished drop before sewing. Pin across the width and stitch near the upper folded edge. For heavy curtain fabric, mitred corners reduce bulk and create a cleaner finish, but a simple double fold works well for basic curtains.
Do not permanently sew the bottom hem until you are confident the length calculation is correct.
Add curtain heading tape
For pencil-pleat or similar curtains, heading tape is sewn across the top on the wrong side. Turn and press the top edge first if required by the tape and pattern. Position the tape level across the curtain, leaving the pull cords accessible at the correct edge. Pin the tape carefully. Sew along the designated stitching lines, normally close to the top and bottom of the tape, taking care not to sew across the gathering cords.
Backstitch at the ends. Follow the tape manufacturer's instructions because different tapes have different rows and hook positions.
Gather the curtain
Once the tape is attached, tie the cords securely at one end. Pull the cords from the other end until the curtain reaches the required gathered width. Spread the gathers evenly. Tie the loose cords in a removable bundle rather than cutting them off. Keeping the cord length allows the curtain to be flattened again for cleaning. Insert the curtain hooks evenly in the appropriate tape pockets.
Hang the curtain and adjust the gathers.
Let the curtains hang before final adjustment
New curtains often settle after hanging. If the floor is uneven or the fabric is heavy, a mathematically perfect bench measurement can still look slightly wrong in position. For expensive fabric, one careful method is to make the curtain slightly long, hang it, let it settle and mark the final hem in the room. This takes longer but gives better floor clearance.
Press as you sew
Pressing is what makes homemade curtains look finished rather than merely stitched. Press side hems before sewing. Press joining seams open. Press the bottom hem. Use a temperature suitable for the fabric and a pressing cloth where necessary. Test a scrap first, especially with synthetic, velvet, coated or delicate furnishing fabrics. Do not iron directly over finishes that can melt or mark.
A simple order of work
For straightforward unlined pencil-pleat curtains:
- Measure the track and finished drop.
- Calculate fullness and fabric.
- Pre-shrink if appropriate.
- Cut and pattern-match the drops.
- Join widths.
- Sew side hems.
- Sew the bottom hem.
- Finish the top.
- Sew on heading tape.
- Gather to width.
- Add hooks and hang.
- Make small final adjustments.
Curtains reward accurate preparation more than complicated sewing. Measure twice, press every fold and keep the long seams straight; the sewing machine then has a very simple job.
Sources checked: The Sewing Directory: pencil pleat curtain tutorial and Just Fabrics: measuring for pencil pleats.