I picked up a cute summer top at a thrift store years ago. It is too small now, so I want to use it as a template to make a roomier copy.
Without even taking apart the seams I study the construction. I can see that it is basically a tri-panel back and a a tri-panel front. All pieces are straight rectangles. Elastic across the upper back and under the arms gives the garment shape.
Luckily I have inherited an abundance of stash material, some of which is perfect for mock-ups. I cut out two sets of pattern pieces, adding in seam allowances. One set I assemble, just with basting. I try it on and mark where it needs to be altered. I make these changes to the second cutout set, and use it to make the tissue pattern.
Now, if your fashion fabric is really expensive, and the changes significant, it may be wise to make a muslin. But I jumped right in and cut my final pieces. To calculate how much material you’ll need, lay out the tissue pattern pieces on any folded 45″ or 60″ wide fabric. Arrange centre panels and facings along folds, and don’t under-estimate for extras such as facings, straps, sleeve bindings, straps and plackets.
Do make a plan for a logical order of assembly. Every garment is different, but look at the parts of it as separate units, and shaping details of each should be completed before being joined to the other pieces.
Here is the order I followed for my smock tank:
- Assemble three front panels (flat fell seams).
- Sew front facing to neck.
- On the back centre panel, sew on elastic casings. Insert elastic.
- Assemble all three back panels, being sure to catch ends of elastic in seams to secure.
- Sew up strap seam with side ruffle.
- Attach shoulder straps at garment back
- Sew up side seams.
- Add bias tape facing and insert elastic under arms.
- Join straps at front.
- Add ruffle hem.