ブラック・グリーン＆グレー バルーンモザイク レター入りバルーンパック（45個入り）

The letters are a nice, thick cardstock that holds up well while you're assembling the arch. I used them for a 40th birthday backdrop and the whole kit made setup surprisingly easy.

The colors are so rich once inflated, and the pack comes with plenty of extras in case anything pops. It took me about an hour to set up the whole mosaic for my daughter's party, and the letters stayed put without any shifting.

I was worried the letters would be too flimsy, but they held up perfectly while I was assembling the balloon arch. The mix of black, green, and grey really made the design pop for my son's party.