If a tattoo artist doesn't reply to your email, be patient. Remember that they are often busy with clients and may not have had a chance to respond yet. Wait for about a week, then send a polite follow-up email to check if they received your initial message. If you still don't hear back, it's possible that they may be fully booked, missed your email, or your proposal isn't something they can take on at the moment. At this point, you might want to consider reaching out to other tattoo artists who align with your desired style.