Shalom and thank you for your question. Today microblading may be an accepted cosmetic procedure, but you are correct to check out it’s Halachic (Jewish legal) acceptability. It would present a problem under two conditions: A. If the procedure would be totally permanent, and B. If the ‘tattoo’ is made with writing.
To clarify further, we are referring to a sign on the skin which is made by making a slit or penetration through the layers of skin, reaching the flesh, into which color is inserted, or by applying color and then making a slit or penetration which causes the color to be absorbed deeper into the skin. Either way is considered to be a tattoo which is forbidden if the two above-mentioned conditions are also present.
There are opinions in Jewish law which allow such a marking to be made if it is not totally permanent.
In the Halachic work called Techumin, volumes 10 and 18, there are two sections dealing with permanent make-up and ‘applied’ eyebrows. First the technical procedure is discussed, and various explanations are presented in order to allow these procedures. There are divergent opinions as to whether or not the Torah forbids only making a tattoo in writing, and thus if there is no writing, but only an impression, the procedure is not forbidden by the Torah. It is possible that when there was no intention of forming letters, then there is no prohibition from the Torah, especially when we are talking about non-permanent impressions on the skin.
There is another issue to be taken into consideration. If tattooing is done as a form of idol-worship, this would be a direct prohibition against Torah law. If however, there is definitely no such intention or connection, then it is not prohibited.
To summarize: Writing which penetrates the skin to the flesh and lasts for a long time would definitely be prohibited, (and there is no intention to write,) but if it is not permanent it is permitted.
The above is the legal aspect specific to the tattoo issue.
In addition, we are instructed by the Torah to guard our health. Perhaps it is worthwhile to verify that there have been no known serious side-effects from these procedures, and that if you undertake to have them done, it will be through agents that are recommended and well qualified, who can take responsibility.
