What yarn is best for blankets for hdc stitch blankets ?

When selecting yarn, always select a yarn you love and enjoy working with; this will make your process more enjoyable, and you are more likely to finish your project.

Consider yarn, which is readily available in a wide range of colors. Crochet blankets can be real stash busters, so select a yarn that you can easily stock up on if you run out of your favorite color. Always consider a yarn that is budget-friendly towards your means, you don't want to break the bank just because someone tells you this yarn is best for this blanket, there are great budget-friendly options available, that are very soft, and with a wide color selection, you should be able to still create a beautiful crochet blanket.

When choosing yarn, also consider the weight and texture based on the kind of blanket you want to make—whether you prefer a soft, plush texture or something sturdier.

Which Yarn weight is best for a crochet blanket?

Depends on the type of blanket you want to create. 

Worsted Weight (Medium, 4) 
By far the most popular yarn weight for crochet blankets. It strikes a good balance between thickness and ease of use. It works up quickly and creates a blanket that’s warm but not too heavy. Most standard blanket patterns use worsted-weight yarn.

Bulky (Weight 5) 
If you're looking for a thick, cozy, and warm blanket, bulky yarn is a great choice. It works up very quickly, which is great for large projects. However, the final blanket will be heavier and thicker.

Aran (Light Worsted, Weight 4)
Aran weight yarn is very similar to worsted but is a little thicker. It creates a denser, warmer fabric, making it a good option for winter blankets.

DK (Double Knit, Weight 3) 
My personal favorite :) Double-knit yarn is great for when you want a lighter, drapey blanket that’s perfect for warmer climates; DK weight yarn works well. It’s not too heavy, so it creates a softer, more delicate texture compared to heavier yarns. I live in a warmer climate, where there might be cold spells 3 to 5 months of the year, so using a lightweight yarn for me helps me make items that can be used all year round.

Super Bulky (Weight 6)
This weight is for those looking for a thick, plush blanket that works up extremely fast. It’s great for blankets that are meant to be extra cozy and warm, but it can be a bit stiff for some types of designs. Also note that when using bulky yarn you will need to make a size swatch beforehand, as you don't want to end up with an overly large blanket or project.

For most crochet blankets, worsted weight (4) is the go-to choice because of its versatility, ease of use, and balanced feel. If you want something quicker and extra cozy, you might choose bulky (5) or super bulky (6). If you're looking for something lighter, DK (3) would be ideal.

It's always best to make a size swatch before you create your blanket to ensure you end up with the correct size you want to make. 

Make sure you check the pattern notes on which patterns include resizing information, especially if you know that you won't use the yarn specified in the pattern.

How much yarn will you need?

When making a blanket , choose a yarn brand which is readily available to you. 
You don't want to run out of yarn halfway through a beautiful project. If you have limited yarn available, make smaller projects like bags, hats, scarfs, or toys.