Fully improve the tailor's work area.
UPDATE: With the addition of the Scissors, you now only need to make 9 of the 12 upgrades (Dummies, Work table, Spinning Wheel, Scissors, 3 levels each) to get this achievement.
Tailorshop achievement button
Reward: You can buy 250 token little Katze der Schneiderin
Achievements list
Reward for tailorshop is granted by message and displayed at the improvements page.
Katze der Schneiderin (Tailor's cat) is the tailorshop achievement reward. This is another mistake of the programmers to have this display in german.
A fully upgraded tailor workshop with mahogany flooring.