15 cm placement box
The guide marks the exact opening, center cutting line, and triangular corner cuts used to turn clean ends.
Welt pocket pattern
Create a welt pocket pattern
Generate a coordinated placement guide, reinforcement patch, welt pieces, single-welt upper facing, and pocket bag for jackets, trousers, vests, skirts, or coats. Set the opening, finished welt width, angle, bag size, construction, and seam allowance, then export the same measured geometry for print.
Sew a complete sample first
A welt opening cannot be closed invisibly after cutting. Test the exact fabric, interfacing, stitch length, corner cuts, pressing, and bag attachment before sewing the garment.
Placement, welt, and bag pieces
Real generated example
One measurement set, a complete coordinated pocket set
Production geometryThis example is rendered by the welt-pocket generator using a 15 cm opening, 1.5 cm finished welt, 19 cm bag width, 22 cm depth, and double-welt construction. The opening, reinforcement, strip dimensions, and bag are calculated together rather than drawn as unrelated templates.
Two matched strips
Double-welt mode labels the strip to cut twice and includes fold and stitching guides around the finished width.
19 × 22 cm capacity
The pocket bag stays wider than the opening so its side seams clear the fragile opening corners.
One geometry for every file
Preview, SVG, copyshop PDF, and tiled A4 PDF are produced from the same dimensions and marks.
For these settings, the generator expands the 15 cm opening with 2.5 cm end extensions and seam allowances to calculate the welt cutting length. It also protects a minimum 4 cm difference between the opening and bag width.
Use SVG for vector editing, copyshop PDF for a full-size sheet, or tiled A4 PDF for home printing. Every printable version includes a 5 × 5 cm test square.
Using the generated pieces
What each pattern element does
The download separates marking, reinforcement, visible self-fabric pieces, and pocketing. These are not layers to stack together at once. The upper facing appears only for single-welt construction because it finishes the edge opposite the visible welt. Use every label at its stated construction stage.
Placement guide: transfer, do not cut
Place the guide on the garment panel where the finished opening should sit. The outer pale rectangle only gives handling space; the dark inner box defines the finished opening and the dashed center is the cutting line. The diagonal marks show where the center cut branches toward the stitched corners.
Align the long center line with the intended pocket angle and check that both ends are equally distant from nearby seams or darts.
Trace the inner rectangle, endpoints, center line, and corner diagonals with removable chalk or thread tracing.
Remove the paper before sewing. Never cut the garment around the outer edge of this guide.
Welt strip: interface, fold, and stitch
Cut the strip on straight grain unless the garment design specifically requires another direction. Double-welt construction uses two identical strips; single-welt construction uses one. The dashed fold line establishes the visible lip, while the lighter parallel lines help position the stitching distance.
Transfer the fold and stitching references to the wrong side, then apply lightweight interfacing without shrinking the strip.
Press the fold accurately and match the strip center and endpoints to the garment opening before basting.
Keep the seam allowance behind the welt after turning so it does not roll into the visible opening.
Reinforcement patch: support the irreversible cut
The patch extends at least 3 cm beyond the calculated opening. Cut it from a compatible fusible or sew-in interfacing, test the bonding method on a scrap, and transfer the dashed opening reference after the patch is stable and cool.
Choose support that prevents stretching without leaving a stiff rectangle visible from the right side.
Center the dashed opening box on the garment marking and keep the patch grain stable.
Fuse or baste before stitching the welts; never try to slide reinforcement through the opening afterward.
Upper facing: finish the opposite opening edge
Single-welt mode adds a self-fabric upper facing because one welt finishes only the lower side of the opening. Stitch the marked edge to the upper opening line, turn it inside with the welt, then join the upper pocket-bag half to its free edge.
Cut one facing from self fabric so pocketing cannot show above the single welt.
Match its center and endpoints to the upper stitching line before the garment is cut.
For double-welt construction this separate piece is omitted because the second welt finishes the upper edge.
Pocket bag: cut two mirrored pieces
The outer solid line is the cutting edge with seam allowance included; the inner dashed line is the stitching path. Cut two mirrored pieces so their right sides can face when the perimeter is closed. The grainline keeps the bag hanging vertically instead of twisting inside the garment.
Mark which bag half attaches to the upper welt allowance and which attaches to the lower allowance or facing.
Keep the bag top clear of the triangular corner tabs until those tabs have been secured.
After attachment, let the bag hang naturally before trimming or stitching its perimeter.
Construction choice
Single welt or double welt
Both options use the same opening logic, but the visible finish and strip count differ. Choose before cutting because the markings and fabric preparation must match the intended construction.
One welt covers the opening edge
A single welt creates one visible folded lip, often combined with a flap or used as a clean horizontal detail. The strip needs accurate interfacing and a consistent fold so the finished welt stays even from end to end.
Two welts meet at the center
A double welt uses two matching strips that fill the opening symmetrically. Precise parallel stitching is essential: a small difference in seam distance changes the visible widths and can twist the finished frame.
Construction sequence
How to sew the generated welt pocket
Complete the operations in order. Do not cut the garment opening until the welts are attached with two verified parallel seams: once the center line is cut, the placement cannot be moved and the opening cannot be returned to its original state.
Test the complete pocket
Print at 100%, confirm the 5 × 5 cm square, and sew one sample in the final fabric with the intended interfacing. Record any change to welt width, needle, stitch length, or pressing before working on the garment.
Stabilize the garment
Fuse an interfacing patch to the wrong side that extends at least 2–3 cm beyond every side of the opening. Let it cool flat, then use the placement guide to transfer the box, center line, endpoints, and diagonals.
Prepare the welt strips
Cut one strip for a single welt or two for a double welt, apply interfacing, transfer the fold line, and press. Mark each strip center and both opening endpoints so they can be matched without stretching.
Place and baste
Lay the prepared strips on the garment right side with raw edges toward the center cutting line. Match centers and endpoints. Baste or glue-baste outside the stitching lines, then compare the two seam distances with a ruler.
Stitch the opening
Sew straight, parallel lines exactly between the endpoint marks. Backstitch only at the ends and do not cross into the diagonal corner area. Turn the work over and confirm that both seams start and stop on the same cross lines.
Cut the center and corners
Cut through the garment and interfacing along the center line, stopping before each end. Clip diagonally to form two small triangles, approaching the final stitch without severing it. Under-clipped corners pucker; over-cut corners create holes.
Turn, square, and press
Pull the welt strips through to the wrong side, arrange the visible lips, and roll the seam lines just out of sight. From the wrong side, pull each triangular tab flat and stitch it securely across the welt ends. Press with a cloth and clapper if suitable.
Attach and close the bag
For a double welt, sew one bag half to each welt allowance. For a single welt, attach the lower half to the welt allowance and the upper half to the facing. Let both halves fall toward the hem, align them right sides together, and stitch the perimeter without catching the garment.
Quality control
Fix the cause, not only the visible defect
Inspect the sample before repeating the process on the garment. Most welt-pocket problems come from four measurable causes: unequal seam distance, inaccurate corner clipping, insufficient stabilization, or tension from the bag.
One lip is wider or the center gap wanders
Measure from the center cutting line to both stitched seams. If the distances differ, the welts cannot finish equally even when their strips were cut correctly. Restitch the sample with a fixed seam guide and match the endpoint marks before cutting.
The short ends will not form a clean rectangle
Check that the two seams stop on the same perpendicular line and that each diagonal clip reaches close to the final stitch. A clip that stops short traps fabric; a clip beyond the seam weakens the corner. Secure the triangular tab while holding the opening square.
The pocket spreads or sinks into the garment
The opening may have stretched during handling, the interfacing may be too soft, or the bag may be pulling downward. Stabilize before marking, avoid steam distortion, press rather than drag the iron, and support the bag from a stable seam allowance where appropriate.
The pocket bag shows, bunches, or turns inside
Confirm that two mirrored halves were cut, their grainlines point in the same direction, and the upper and lower attachment edges were not swapped. Before closing the perimeter, let the bag hang freely and smooth it away from the opening without stretching either half.
Related guides
Project
Tailored trousers, end to end
Six generators assembled into one garment: the order to draft them, where the pieces have to agree, fabric for the whole pair, and the sewing sequence.
New TemplatePatch Pocket
Generate a clean patch pocket pattern with rounded, square, or angled bottom shapes.
New TemplateIn-seam Pocket
Generate a hidden pocket bag for skirts, dresses, pants, and shorts.
Trouser and skirt detailSlant Pocket Pattern
Generate a diagonal or curved front-pocket opening with matched pocket bags, a self-fabric facing, waist anchors, notches, and seam allowances.
ConstructionSeam and hem allowances
Read solid seam lines, dashed cutting lines, construction seam allowance, hem allowance, curves, and corners.
Technical references
Construction guidance behind the practical checks
The generator calculates pattern geometry; these independent educational resources support the sewing sequence, corner handling, pocket-bag closure, and the need to test interfacing on the intended fabric.
Tailoring a welt pocket with flap
The University of Kentucky Cooperative Extension illustrates turning the pocket through the opening, stitching the triangular ends, attaching the pocket back, and closing the pouch.
Testing compatible interfacing
New Mexico State University recommends selecting interfacing compatible with the fashion fabric and testing the required steam and pressure on a sample before committing to the garment.
Welt pocket drafting guide
What to check before cutting the garment
The generator supplies measured pattern elements, but the final quality depends on fabric preparation, exact marking, controlled cutting, and pressing. Review these decisions before committing to the garment panel.
Choose a stable, usable location
Keep the opening away from bulky seam intersections, darts, and edges unless the design accounts for them. Confirm that a hand can enter comfortably and that the pocket bag fits inside the garment without reaching the hem or closure.
Measure the functional length
Opening length should suit the wearer and garment scale. A decorative chest pocket may be shorter than a trouser or coat pocket. Test the intended angle and hand access on the pattern before selecting the final value.
Finished width is not cut width
The visible welt is only part of the strip. The cutting width also includes the folded return and seam allowances. Use the generated fold and stitching guides instead of cutting a strip equal to the visible width.
Stabilize the opening area
A welt opening is cut into the garment, so distortion is difficult to undo. Interface beyond every side of the marked box. Lightweight fabrics may need a crisp organza or fusible patch; heavy cloth needs support without a hard ridge.
Stop stitching at identical endpoints
The triangular corner cuts turn cleanly only when both seams stop at the same cross marks. Cut close to, but not through, the stitches. Unequal endpoints create puckers or small holes at the corners.
Test the complete construction
Use the final fabric, interfacing, thread, stitch length, and pressing method for a sample. Check symmetry, corner strength, bulk, and whether the bag shows through before sewing the actual garment.
How and when
Generated from application code
This generator converts the entered measurements into vector geometry. Where a construction has related seams, the software can calculate their lengths; preview, SVG, copyshop PDF, and tiled A4 PDF are produced from the same geometry. These software checks do not replace printing, sewing, or fitting a test sample.
Last recorded review of the generator implementation and documentation: 2026-08-24. The output has not been certified through physical production testing; verify measurements, print scale, seam relationships, fabric behaviour, and fit for your project.
Common questions
Welt pocket pattern FAQ
What pieces does the generator create?
It creates a placement guide, a reinforcement patch, a welt strip sized for the selected construction, and a pocket-bag piece. Single-welt mode also creates a self-fabric upper facing; double-welt mode instead instructs you to cut two matching welt strips.
Is the welt width finished or cutting width?
The entered welt width is the finished visible width of one welt. The generator calculates a wider cutting strip that includes the folded return and seam allowances.
Does the pattern include seam allowance?
Yes. The selected seam allowance is included in the welt-strip cutting dimensions and around the pocket bag. The placement guide represents garment markings and is not a fabric cutting piece.
Can I use the pattern for angled pockets?
Yes. Choose the placement angle in the generator. The guide rotates the opening relative to a fixed garment-grain reference, while the welt, facing, and pocket pieces keep their own cutting direction. Confirm hand access and bag clearance on the garment before transferring the guide.
Why should I sew a sample first?
The garment opening is irreversible once cut. A sample verifies interfacing, stitch accuracy, corner cutting, welt width, pressing, and fabric bulk before the final garment is at risk.
From dimensions to printable pieces
01
Choose the opening
Set the visible opening length and the finished width of one welt.
02
Select construction
Choose one wider welt or two balanced welts and size the pocket bag.
03
Export and test
Print at 100%, transfer the placement box, and sew a sample before the garment.