Comments update: Marc Newson faced a backlash over his decision to use mammoth ivory in an £82,000 tea set this week on Dezeen. Read on for more on this and explore our comments page to keep up to date with the latest discussions.

Taken to tusk: each piece in the limited-edition tea set created by Newson for metalware brand Georg Jensen is made from hand-hammered silver and comprises "responsibly sourced" mammoth-ivory handles. But commenters say that using the tusks of an extinct species supports the trade for ivory sourced from endangered animals.

"The use of mammoth ivory is utterly repulsive," wrote Dean. "It spoils what is otherwise a thoughtful design."

"By using any ivory, be it elephant or mammoth, you are keeping the demand for the ivory trade alive, resulting in continued poaching," added another reader.

Not everyone agreed. "Could one argue using tusks from extinct animals, which is the case in this situation, doesn't do any damage at all?" asked a commenter calling themselves Fresh10, while Friardo pointed out that dead things "have always been used by remaining living organisms". Read the comments on this story »

On the buses: London is getting a smaller version of Thomas Heatherwick's New Routemaster bus. But the designer isn't involved – and readers think it shows.

"Heatherwick's feels like the concept car and this new iteration is the boring, watered-down road-legal model," said Richard, while Jose compared the differences in each bus to products created by technology companies Apple and Samsung.

"Looks like a much-needed improvement with more glazing area," countered a guest commenter. "Heatherwick's version always feels dark and gloomy internally." Read the comments on this story »

Tesla vs Apple: as the battle for dominance in the electric-car market heats up, Tesla's billionaire founder Elon Musk mocked Apple's reported plans to launch a model by 2019. Many readers felt his comments were unjustified; others were excited at the prospect of vast resources being piled into the development of electric vehicles.

"The more companies that are working on electric cars, the better in my opinion," said HJ. A little competition can go a long way."

"[Musk] is underestimating the role design and aesthetics play in this," added Stephen. "Tesla cars are the automotive equivalent of a Samsung phone; I would never buy one because they are generic, bordering on ugly."

One commenter excitedly compared Tesla's founder to late Apple CEO Steve Jobs while others added to doubts over the of Tesla's design credentials.

"I'm all for Apple creating much more elegant models of electric cars," said Spadestick. "Tesla vehicles may be engineered well but are currently designed by the worst designers." Read the comments on this story »

Lets twist again: BIG's plans for an art museum that will twist across a Norwegian river split the opinion of readers. Many praised the design, while others felt the structure was too similar to many other built and proposed projects.

"Twist and shout architecture, again," wrote Mimi, while Charles questioned whether its design would let too much sunlight and therefore damage exhibits.

"A museum that allows too much sunlight to enter will fail as a museum," he said. "Radiation is crucial to artwork, and the standard is to let 2-5 per cent of sunlight at a maximum. Otherwise, no paper no paint; only sculptures."

"It's an innovative structure," replied Grace who asked why architecture by the Danish firm attracted so many negative comments. "I'd love to visit it when it's built." Read the comments on this story »