Most companies produced hot-iron transfers that were single-use -- the unused pattern had raised ink that transferred to the fabric.If the design is composed of small dots, it's a Numo style pattern.They were produced in large numbers and, happily, many have survived.
Vogart switched to multi-use transfers and updated their packaging in the mid-1960s.
The first Vogart transfers came to market in the early 1940s and were numbered from 101.
Although you'll also find transfers with numbers in the 200s, 600s and 700s, there are actually only about 200 unique patterns.
At the beginning of this period many transfers were perforated patterns -- the design was composed of small holes in the paper and transferred to fabric by forcing black powder through the holes.
Embroidery designs transferred to linens by rubbing and/or moistening the pattern made a brief early appearance, but the hot iron process quickly became the norm.