Double Doodles can have straight hair, although this is quite a rare occurrence and you’re much more likely to encounter Double Doodles with coats that are either wavy or curly.
The reason why Double Doodles occasionally have straight coats is that some Goldendoodles and Labradoodles physically take after either their Golden Retriever or Labrador parent more than their Poodle parent.
This means that certain Labradoodles and Goldendoodles may have straight coats (although, again, this is quite rare), and they may pass this trait on to Double Doodle offspring.
Please bear in mind that it’s difficult to tell whether a Double Doodle will have a straight, wavy, or curly coat until they are older. This is because puppies’ coats are much shorter than adult coats, and this can make curly coats initially appear much straighter than they will end up being as the dog matures.
While Double Doodles with straight hair often aren’t prioritized by breeders or buyers because they don’t fit the typical aesthetic profile of the breed, a straight-haired Double Doodle can be a blessing when it comes to grooming since straight coats are usually easier to work with than curly ones because it’s easier to prevent tangling and matting.