A friend asked me if I had tried this method to copy a garment. At first I was pretty skeptical because I have copied garments by taking them apart and by scratching off a pattern from clothing that I did not take apart. Either way there are several steps and accuracy is easier if you have the pieces to lay flat. I was not excited about using tape on a garment I planned to wear again, but 3M's blue painter's tape is made to be less tacky so there is no residue. As it turns out this is probably the easiest way to copy a garment and the bonus is that you can mark your exact seam lines to insure a proper fit. Here is how.
Step 1: You Will Need These Items
A clean, fresh pressed garment that fits perfectly.
3M blue painter's tape, I used two sizes the slightly less than an inch wide size and the two inch wide size, you could use wider too, just depends on how much space you need to cover, you don't have to have two sizes, but I will explain in the instructions why it is useful.
Tissue paper, tracing paper or other paper to place on the sticky side of the pattern once completed.
Step 2: Examine Your Original Garment to Determine What You Need
Examine your garment to determine what you can trace without needing the tape, what you probably do not need to tape and what pieces you do need to tape. My garment is a shirt with a collar, collar stand, front button band, center front piece, front side piece, center back piece with a seam down the center, back side piece, and 3/4 length sleeves.
The collar and collar stand were easy to lay flat and trace around the outer edges so I did not use any tape for them. I also did not trace the front button and button hole bands because it is just a straight piece of fabric, folded with seam allowances on both sides. I can measure this and cut it without needing any pattern at all, but if you want you can tape it too.
That left five pieces that I needed to tape. My shirt did not have any darts because it has princesses seams so that kept this fairly simple. If your garment has pockets and or darts you will need to include these details and it may require a little more work. If you need help with this just let me know in the comments I will add an additional Instructable to cover that topic. While I did tape all five pieces I will just show how to tape one piece. Do this for each each piece you need to trace.
Because each piece is cut on folded fabric you will only have to trace half of your garment. If you start on the left side use only the left side to trace your pieces, or if you start on the right side, use only the pieces on the right side. This will keep the same side up and make it easier when you get ready to cut out the pattern.
I started with the left center front and worked my way to the center back. Make sure the garment is clean and freshly pressed so it will be easy to lay each piece flat.
Step 3: Taping the Pieces
Lay the section you are ready to tape as flat as possible. Start by taping exactly on the seam line at the outer edges of this piece with the narrow painters tape. Where your garment has curves, tear the tape in short pieces and add the pieces around the curved seams so that all of the fabric is covered just to the seam. The smaller pieces make it easier to work your way around the curves. Where there are no curves you can use longer pieces of tape. See the first picture above, especially the curved part by the sleeve seam. Once your edges are complete you can use the wider tape for the fill area between the seams. Be sure to over lap where the tape edges meet so that it is easier to remove without tearing apart.
When everything is taped edge to edge mark any design notes you will need. This shirt had horizontal tucks down the front which I did not mark. There is a seam in the shirt where this portion is joined to the yoke, but if you leave them out you will not need this mark. If I do include the seam and make the tucks I will sew the tucks before I cut out the pattern. This just makes it easier and eliminates the need to mark them separately on the pattern. If I need to, I can retrace the yoke and tuck portions into two pieces by adding seam allowances a the mark you can see on my pattern. If I do not use the tucks I will not need to make any alteration at all to this pattern. These are the kind of notations you will want on your traced/taped pattern. On this pattern I simply marked the portion that is the yoke and where the seam would go if I need it or where the first tuck is placed when I lay the pattern on the pre-tucked fabric.
The sleeve will require special attention. Because you will not be able to lay the sleeve out flat, trace each side from seam to press line. Put the two pieces together on the paper to make one completed piece.
Step 4: Removing the Taped Piece From the Garment
Once all of the notations are made for seams or details like pockets, button placement or other design details if any, the blue tape can be removed from this section. The edges with the smaller pieces will try to separate in some places and may require special attention. Go slowly and work your way around the edges, moving from one side to the other as needed to keep the tape from ripping or separating.
Step 5: Place the Taped Pattern Piece on Tracing Paper
Once the completed pattern piece is off of the garment place it sticky side down on tracing paper or other paper. Smooth the pattern on the paper, careful not to let it wrinkle. Turn the paper over and use a burnishing tool to get a smooth placement and remove any air pockets. Let the pattern rest while you trace the other pieces. After you have copied all of the other pieces, draw your seam allowances and remove the extra paper from the pattern pieces. Now you have a perfect pattern of a garment you know fits and you still have the original garment in tact.
Step 6: Review of Original Shirt and Test Sew
I used a holiday star print from the stash to test sew this blue tape pattern. I did make one alteration, at the top of the shoulder where the sleeve attaches I took in the sleeve and the shoulder seam 3/4 of an inch to get a better fit at the shoulder. That could have been due to having to tape/trace the sleeve in two pieces. I will mark this alteration on my pattern for future reference.
Step 7: Pattern Cut Out
Here is an image of the cut pieces. Note that I added length for the self facing at the end of the sleeve. The extra length includes enough fabric for the back side of the fold up cuff and hem. Everything else was pretty much as traced/taped.