Front borders of a cardigan are either made by knitting them separately, by holding extra stitches of the lower border to be worked later, or by picking up stitches along front edges and back neck. My favorite way to knit a border is by holding stitches from the lower front edge, which I work later. The reason I like this method is there is less chance of the border flaring or puckering. Whichever way you choose to make the borders, the spots where you want to place the buttonholes need to be marked.
Pattern instructions will tell you the number of buttonholes to make and usually read something like “…mark positions for the total number of buttonholes on the button band, the first to come 1/2in (1cm) from bottom edge and the last 1/2in (1cm) from neck edge…work buttonhole border as given for button band with the addition of buttonholes to correspond to markers…”. You’ll find most instructions have you work the button border first, followed by the buttonhole border. I do not mark the button border, but instead mark the front edge where I will be placing the buttonhole border. As I’m knitting the buttonhole border, I make a buttonhole where the mark is. It’s just easier then trying to line it up with the button band to figure out where each buttonhole should go.
Steps: At the front edge where the buttonhole border is going to be placed, mark with pins the two positions for buttonholes near the neck and bottom edge as described in the pattern instructions. Measure the length between these two pins and divide this figure by the total number of buttonholes minus one. This figure will give you the spacing measurement between each buttonhole. Mark the remaining buttonhole positions with pins according to this measurement. For example, a pattern asks you to mark positions for 7 buttonholes, the first to come 1cm from both the neck and bottom edge. The length between these two markers = 48cm, therefore 7-1=6 buttonholes, 48 divided by 6 = 8. Place the remaining 5 buttonholes 8cm apart between the first and last buttonhole.
I like to mark using a modified version of tailor’s tacks, a sewing technique used to transfer pattern symbols onto fabric. Insert a tapestry needle threaded with contrasting colored yarn through a stitch close to the edge at the pin marks, but don’t split the stitches. Loosely secure by going back through the stitch leaving short ends. Work the border as per the pattern instructions inserting the buttonholes aligned with the tacks. These yarn ends are easy to remove when the border is complete. You can also use this technique to mark where the buttons are to be sewn.
It should now be easier to add the buttonholes and they will be evenly spaced.