Like any good sewing project, I had to make the vest twice to make it just right, but WOW was that worthwhile. The fabric is a thin wool suiting material on the outside and the vest is lined with normal lining material (I think it is acetate). The pants are unlined. The bow tie is made of silk and fusible cotton and velcro in the back.
Let's start with the vest. This was made using Simplicity 8442, which is a vintage pattern. The first rendition of the vest is in the top photo. It is a size 2T and the arms and shoulders fit right, but it was too short. The second rendition is in the other photos and I lengthened the pattern at the waist by nearly three inches. The bottom photo shows off the vest buckle (Dritz nickel). I took the buttons off old men's khaki pants. The pattern was easy enough to follow and has you turn and topstitch the vest. The sides under the armholes are left open and closed with a seam you can see from the inside. In my first pass at this, I closed them up, which made the armholes a bit smaller than they were meant to be. I used pinking shears on all the seams since that wool keep unraveling and frustrating me. The lining really helped keep it in check.
For the pants, I used my favorite pants pattern. I used the larger size, since the pattern works best on stretchy materials and I didn't want it to be too tight. I pinked the seams before using a zig-zag overstitch, and I added a topstitch around the waist to make it more formal. I also ironed a crease into the pants to make them look dressier. I chose to do a normal hem instead of a blind hem, but a blind hem would work nicely here. The fabric was fairly difficult to work with. I felt like every time I stitched with a thin seam allowance, the fabric would start to unravel. Pinking the seams seemed to help a bit.
I made two pairs of the pants in case they get soiled on the event night (which is likely since the wearer is nearly two and likes to move around).
The bow tie was made using Little Londyn's Little Guy Ties pattern for the Studious Guy Bowtie. It was really quick and easy to make, and it super cute. I like how it velcros in the back. If I'd make it again, I would add an inch to the neck band, to give him a little room to grow.