Ironing is important for an embroidered fabric and it requires some skill and the observance of some fundamental rules, both to correct any imperfections and to enhance the processing of the artifacts.
If the already washed fabric is removed from the drying when it's still wet, it is ready for ironing; otherwise, it should be sprayed with water in a uniform manner and wrapped in a towel, wet well, for a few minutes. This is followed by ironing, after adjusting the iron on a medium-high temperature; if you need to iron linen, the fabric should be well extended with the straight side down on the sponge, ironing the cloth backhand.
Some precautions: suppose you have to stretch a centerpiece with slip-off on all four sides and embroidery center; starting from the center, whether there's the central embroidery with circular motives, or not, the ironing starts first horizontally and then vertically pushing the fabric to the outside.
Completed this first phase, the edges are ironed without pulling them so they do not sway, but it's possible to use more steam by placing the iron to remove the unsightly sway; if necessary, you can spray a little primer (however this operation should be avoided if the garment will be stored for a long time). With such an ironing technique the embroidery will stand out and it will be easy to obtain straight edges.