The second most popular question I see asked about heat transfer vinyl is how to know what size to make your design and where to line it up on the shirt.
Preferences in design sizing and where to center your design might vary depending on what you are working on, but there are some general sizing and placement guides you can follow.
In general- adult sized shirt designs should be between 11 and 14 inches. For kids sized shirts, you only need between 5.5 and 9 inches. Of course, the design size can change depending on what you're making, but these are good sizes to start with.
Where to place your design once you have it cut is a little easier.
Start by folding the shirt in half and make a crease down the middle with your iron or heat press. Fold your design in half (fold the non-sticky sides together and make a small crease in the middle of the backing sheet) and then line the two up. To determine how far down on the shirt to go, most people start by lining the design up with the bottom seam of the shirt sleeves. Adjust based on how tall your design is. If you have a very tall skinny design, on most adult shirts, you can measure about 3 inches down from the collar for top placement.
If your shirt has a pocket that you want to put a design on, consider that most pockets are 3.5-5.5 inch square. If you are adding a design to a shirt with a pocket, that is not incorporated into your design, you can usually just pretend the pocket is not there and line up your design like above.
If you are working with baby clothes, the rules are a little different:
Most baby onesies are 7.5-11.25 inches wide and 12.25-17.25 inches tall (depending on size and brand). The diagram above gives you some ideas on alignment options for different shaped designs. In general, you can crease the onesie in half and, unless you have a smaller chest design, crease the onesie in half the other way to get cross hairs to align your design with.
Why is placement and sizing so important? Why do people worry? Let's look at an example:
For this outfit I used the "I am brand new" design which is part of our 12 Exclusive Heat Transfer Vinyl Designs that I created. This design comes sized to fit a typical 0-3 month onesie. If you are making a body suit for a smaller baby (maybe in a preemie or newborn size) you will need to make the design a little smaller (5 inches would work well).
Making your own custom shirts is a lot of fun and can make great gifts. You may even be able to start up your own small business! Making sure your designs are the right size, and aligned properly, can make all the difference in the end product. I hope you have found these tips helpful!