S.w.a.l.k. stands for 'Sealed With a Little Kiss' and the gorgeous S.w.a.l.k characters from Santoro fit this idea perfectly

S.W.A.L.K. STAMP - A Little Kiss£3.90 S.W.A.L.K. STAMP - After the Rain£3.90 S.W.A.L.K. STAMP - Best Dad£3.90 S.W.A.L.K. STAMP - Best Friends£3.90 S.W.A.L.K. STAMP - Best Mum£3.90 S.W.A.L.K. STAMP - Best Teacher£3.90 S.W.A.L.K. STAMP - Blooming Wonderfull£3.90 S.W.A.L.K. STAMP - Congratulations£3.90 S.W.A.L.K. STAMP - Engaged£3.90 S.W.A.L.K. STAMP - Friends Like You£3.90 S.W.A.L.K. STAMP - Get Well Soon£3.90 S.W.A.L.K. STAMP - Grandpa£3.90 S.W.A.L.K. STAMP - Groovy Granny£3.90 S.W.A.L.K. STAMP - hugs£3.90 S.W.A.L.K. STAMP - I Do£3.90 S.W.A.L.K. STAMP - Little Madam£3.90 S.W.A.L.K. STAMP - Little Note£3.90 S.W.A.L.K. STAMP - My Sister£3.90 S.W.A.L.K. STAMP - Special Little Person£3.90 S.W.A.L.K. STAMP - Thinking of You£3.90