You can really get some large size arrangements using the Grande bricks and Designer blocks from Smithers Oasis. Just make sure you let them soak well as sometimes the bigger blocks can develop an air pocket if not fully soaked. If I have to use them for an arrangement....I let them soak overnight. However, If I get an order for a large scale design same day that I need one of the grande brixks and/ or designer block.....I always have one fully soaked and wrapped in a sealed plastic bag to keep in the water/ moisture.